diff --git a/packages/agent/CHANGELOG.md b/packages/agent/CHANGELOG.md
index e2592c1dc..463cfc99c 100644
--- a/packages/agent/CHANGELOG.md
+++ b/packages/agent/CHANGELOG.md
@@ -1,6 +1,10 @@
 # Changelog
 
 ## [Unreleased]
+### Added
+
+- Added `loadMode` option to `AgentTool` to mark built-in tools as `essential` for initial loading or `discoverable` for search activation
+- Added optional `summary` field to `AgentTool` definitions for one-line text used in tool discovery indexes
 
 ## [14.7.0] - 2026-05-04
 ### Breaking Changes
diff --git a/packages/agent/src/types.ts b/packages/agent/src/types.ts
index 92ce50de0..34de7fa50 100644
--- a/packages/agent/src/types.ts
+++ b/packages/agent/src/types.ts
@@ -248,6 +248,10 @@ export interface AgentTool<TParameters extends TSchema = TSchema, TDetails = any
 	hidden?: boolean;
 	/** If true, tool can stage a pending action that requires explicit resolution via the resolve tool. */
 	deferrable?: boolean;
+	/** Built-in tool loading behavior. "essential" loads initially; "discoverable" can be activated by tool search. */
+	loadMode?: "essential" | "discoverable";
+	/** Short one-line summary used for tool discovery indexes. */
+	summary?: string;
 	/** If true, tool execution ignores abort signals (runs to completion) */
 	nonAbortable?: boolean;
 	/**
diff --git a/packages/coding-agent/CHANGELOG.md b/packages/coding-agent/CHANGELOG.md
index 9989da457..f6926ebc4 100644
--- a/packages/coding-agent/CHANGELOG.md
+++ b/packages/coding-agent/CHANGELOG.md
@@ -1,6 +1,13 @@
 # Changelog
 
 ## [Unreleased]
+### Breaking Changes
+
+- Removed the exported `BUILTIN_TOOL_METADATA` API, including `BuiltinEntry`-style metadata exports and discoverable-built-in helper exports, which will break consumers relying on those symbols
+
+### Changed
+
+- Updated discoverable tool search (`search_tool_bm25` and related discovery metadata) to read each tool’s own `summary` field when present, improving discoverability descriptions for built-in tools
 
 ### Fixed
 
@@ -7822,4 +7829,4 @@ Initial public release.
 - Git branch display in footer
 - Message queueing during streaming responses
 - OAuth integration for Gmail and Google Calendar access
-- HTML export with syntax highlighting and collapsible sections
+- HTML export with syntax highlighting and collapsible sections
\ No newline at end of file
diff --git a/packages/coding-agent/src/edit/index.ts b/packages/coding-agent/src/edit/index.ts
index f028a7d92..f544887e4 100644
--- a/packages/coding-agent/src/edit/index.ts
+++ b/packages/coding-agent/src/edit/index.ts
@@ -246,6 +246,7 @@ async function executeSinglePathEntries(
 export class EditTool implements AgentTool<TInput> {
 	readonly name = "edit";
 	readonly label = "Edit";
+	readonly loadMode = "essential";
 	readonly nonAbortable = true;
 	readonly concurrency = "exclusive";
 	readonly strict = true;
diff --git a/packages/coding-agent/src/lsp/index.ts b/packages/coding-agent/src/lsp/index.ts
index b598869ea..ba45ba1d5 100644
--- a/packages/coding-agent/src/lsp/index.ts
+++ b/packages/coding-agent/src/lsp/index.ts
@@ -1169,6 +1169,8 @@ export function createLspWritethrough(cwd: string, options?: WritethroughOptions
 export class LspTool implements AgentTool<typeof lspSchema, LspToolDetails, Theme> {
 	readonly name = "lsp";
 	readonly label = "LSP";
+	readonly loadMode = "discoverable";
+	readonly summary = "Query LSP (language server) for diagnostics, hover info, and references";
 	readonly description: string;
 	readonly parameters = lspSchema;
 	readonly renderCall = renderCall;
diff --git a/packages/coding-agent/src/sdk.ts b/packages/coding-agent/src/sdk.ts
index 93f8df8b6..92c4c17e1 100644
--- a/packages/coding-agent/src/sdk.ts
+++ b/packages/coding-agent/src/sdk.ts
@@ -116,7 +116,6 @@ import {
 } from "./tool-discovery/tool-index";
 import {
 	BashTool,
-	BUILTIN_TOOL_METADATA,
 	BUILTIN_TOOLS,
 	computeEssentialBuiltinNames,
 	createTools,
@@ -284,7 +283,6 @@ export {
 	// Individual tool classes (for custom usage)
 	BashTool,
 	// Tool classes and factories
-	BUILTIN_TOOL_METADATA,
 	BUILTIN_TOOLS,
 	createTools,
 	EditTool,
@@ -1358,19 +1356,13 @@ export async function createAgentSession(options: CreateAgentSessionOptions = {}
 			toolContextStore.setToolNames(toolNames);
 			const discoverableMCPTools = mcpDiscoveryEnabled ? collectDiscoverableMCPTools(tools.values()) : [];
 			const activeToolNames = new Set(toolNames);
-			const builtinSummaryMap = new Map(
-				Object.entries(BUILTIN_TOOL_METADATA)
-					.filter(([, meta]) => typeof meta.summary === "string")
-					.map(([name, meta]) => [name, meta.summary!] as const),
-			);
 			const discoverableBuiltinTools: DiscoverableTool[] =
 				effectiveDiscoveryMode === "all"
 					? collectDiscoverableTools(
-							Array.from(tools.values()).filter(tool => {
-								const meta = BUILTIN_TOOL_METADATA[tool.name];
-								return meta?.loadMode === "discoverable" && !activeToolNames.has(tool.name);
-							}),
-							{ source: "builtin", summaryMap: builtinSummaryMap },
+							Array.from(tools.values()).filter(
+								tool => tool.loadMode === "discoverable" && !activeToolNames.has(tool.name),
+							),
+							{ source: "builtin" },
 						)
 					: [];
 			const discoverableToolsForDesc: DiscoverableTool[] = [
@@ -1527,9 +1519,9 @@ export async function createAgentSession(options: CreateAgentSessionOptions = {}
 			// activation persistence is a follow-up). MCP names won't collide with built-in names.
 			const restoredDiscoveredNames = new Set(existingSession.selectedMCPToolNames);
 			initialToolNames = initialToolNames.filter(name => {
-				const meta = BUILTIN_TOOL_METADATA[name];
-				if (!meta) return true; // not a built-in — leave MCP/custom/extension to existing logic
-				if (meta.loadMode === "essential") return true;
+				const tool = toolRegistry.get(name);
+				if (!tool?.loadMode) return true; // not a built-in — leave MCP/custom/extension to existing logic
+				if (tool.loadMode === "essential") return true;
 				if (essentialBuiltinNames.has(name)) return true;
 				if (explicitlyRequestedToolNames.has(name)) return true;
 				if (restoredDiscoveredNames.has(name)) return true;
diff --git a/packages/coding-agent/src/session/agent-session.ts b/packages/coding-agent/src/session/agent-session.ts
index ffa10ebf0..fa6189f88 100644
--- a/packages/coding-agent/src/session/agent-session.ts
+++ b/packages/coding-agent/src/session/agent-session.ts
@@ -137,7 +137,6 @@ import {
 } from "../tool-discovery/tool-index";
 import { assertEditableFile } from "../tools/auto-generated-guard";
 import type { CheckpointState } from "../tools/checkpoint";
-import { BUILTIN_TOOL_METADATA } from "../tools/index";
 import { outputMeta } from "../tools/output-meta";
 import { normalizeLocalScheme, resolveToCwd } from "../tools/path-utils";
 import { isAutoQaEnabled } from "../tools/report-tool-issue";
@@ -2307,20 +2306,17 @@ export class AgentSession {
 		return filter?.source ? allTools.filter(t => t.source === filter.source) : allTools;
 	}
 
-	/** Collect built-in tools the model can discover via search_tool_bm25. Restricted to entries
-	 *  whose `BUILTIN_TOOL_METADATA[name].loadMode === "discoverable"`. This keeps hidden/internal
-	 *  tools (resolve, yield, exit_plan_mode, report_finding, report_tool_issue) out of the index
+	/** Collect built-in tools the model can discover via search_tool_bm25. Restricted to tool
+	 *  definitions whose `loadMode === "discoverable"`. This keeps hidden/internal tools
+	 *  (resolve, yield, exit_plan_mode, report_finding, report_tool_issue) out of the index
 	 *  and avoids mislabeling extension/custom default-inactive tools as built-ins. */
 	#collectDiscoverableBuiltinTools(): DiscoverableTool[] {
 		const activeNames = new Set(this.getActiveToolNames());
 		const result: DiscoverableTool[] = [];
-		for (const [name, meta] of Object.entries(BUILTIN_TOOL_METADATA)) {
-			if (meta.loadMode !== "discoverable") continue;
-			if (activeNames.has(name)) continue;
-			const tool = this.#toolRegistry.get(name);
-			if (!tool) continue;
-			const summaryMap = meta.summary ? new Map([[name, meta.summary]]) : undefined;
-			const collected = collectDiscoverableTools([tool], { source: "builtin", summaryMap });
+		for (const tool of this.#toolRegistry.values()) {
+			if (tool.loadMode !== "discoverable") continue;
+			if (activeNames.has(tool.name)) continue;
+			const collected = collectDiscoverableTools([tool], { source: "builtin" });
 			result.push(...collected);
 		}
 		return result;
diff --git a/packages/coding-agent/src/task/index.ts b/packages/coding-agent/src/task/index.ts
index 66fae68b2..8aa4a3d45 100644
--- a/packages/coding-agent/src/task/index.ts
+++ b/packages/coding-agent/src/task/index.ts
@@ -195,7 +195,9 @@ function validateTaskModeParams(simpleMode: TaskSimpleMode, params: TaskParams):
 export class TaskTool implements AgentTool<TSchema, TaskToolDetails, Theme> {
 	readonly name = "task";
 	readonly label = "Task";
+	readonly summary = "Spawn a subagent to complete a parallel task";
 	readonly strict = true;
+	readonly loadMode = "discoverable";
 	readonly renderResult = renderResult;
 	readonly #discoveredAgents: AgentDefinition[];
 	readonly #blockedAgent: string | undefined;
diff --git a/packages/coding-agent/src/tool-discovery/tool-index.ts b/packages/coding-agent/src/tool-discovery/tool-index.ts
index ed408496a..b2ffdc5f8 100644
--- a/packages/coding-agent/src/tool-discovery/tool-index.ts
+++ b/packages/coding-agent/src/tool-discovery/tool-index.ts
@@ -156,12 +156,19 @@ export function getDiscoverableTool(
 		label?: string;
 		description?: string;
 		mcpServerName?: string;
+		summary?: string;
 		mcpToolName?: string;
 		parameters?: unknown;
 	};
 	const source: DiscoverableToolSource = overrides?.source ?? (isMCPToolName(tool.name) ? "mcp" : "builtin");
+	const rawSummary =
+		typeof overrides?.summary === "string"
+			? overrides.summary
+			: typeof toolRecord.summary === "string"
+				? toolRecord.summary
+				: undefined;
 	const rawDescription = typeof toolRecord.description === "string" ? toolRecord.description : "";
-	const summary = overrides?.summary ?? rawDescription.slice(0, 200);
+	const summary = rawSummary ?? rawDescription.slice(0, 200);
 	return {
 		name: tool.name,
 		label: typeof toolRecord.label === "string" ? toolRecord.label : tool.name,
diff --git a/packages/coding-agent/src/tools/ask.ts b/packages/coding-agent/src/tools/ask.ts
index 6f81d985f..2e716c3aa 100644
--- a/packages/coding-agent/src/tools/ask.ts
+++ b/packages/coding-agent/src/tools/ask.ts
@@ -379,9 +379,11 @@ type AskParams = AskToolInput;
 export class AskTool implements AgentTool<typeof askSchema, AskToolDetails> {
 	readonly name = "ask";
 	readonly label = "Ask";
+	readonly summary = "Ask the user a clarifying question";
 	readonly description: string;
 	readonly parameters = askSchema;
 	readonly strict = true;
+	readonly loadMode = "discoverable";
 
 	constructor(private readonly session: ToolSession) {
 		this.description = prompt.render(askDescription);
diff --git a/packages/coding-agent/src/tools/ast-edit.ts b/packages/coding-agent/src/tools/ast-edit.ts
index 7cd23d3a3..438218355 100644
--- a/packages/coding-agent/src/tools/ast-edit.ts
+++ b/packages/coding-agent/src/tools/ast-edit.ts
@@ -167,10 +167,12 @@ export interface AstEditToolDetails {
 export class AstEditTool implements AgentTool<typeof astEditSchema, AstEditToolDetails> {
 	readonly name = "ast_edit";
 	readonly label = "AST Edit";
+	readonly summary = "Perform AST-aware code edits (structural refactoring)";
 	readonly description: string;
 	readonly parameters = astEditSchema;
 	readonly strict = true;
 	readonly deferrable = true;
+	readonly loadMode = "discoverable";
 	constructor(private readonly session: ToolSession) {
 		this.description = prompt.render(astEditDescription);
 	}
diff --git a/packages/coding-agent/src/tools/ast-grep.ts b/packages/coding-agent/src/tools/ast-grep.ts
index 42a767e16..582f1e0cc 100644
--- a/packages/coding-agent/src/tools/ast-grep.ts
+++ b/packages/coding-agent/src/tools/ast-grep.ts
@@ -122,9 +122,11 @@ export interface AstGrepToolDetails {
 export class AstGrepTool implements AgentTool<typeof astGrepSchema, AstGrepToolDetails> {
 	readonly name = "ast_grep";
 	readonly label = "AST Grep";
+	readonly summary = "Search code with AST patterns (structural grep)";
 	readonly description: string;
 	readonly parameters = astGrepSchema;
 	readonly strict = true;
+	readonly loadMode = "discoverable";
 
 	constructor(private readonly session: ToolSession) {
 		this.description = prompt.render(astGrepDescription);
diff --git a/packages/coding-agent/src/tools/bash.ts b/packages/coding-agent/src/tools/bash.ts
index 9130c7d58..260fcc28f 100644
--- a/packages/coding-agent/src/tools/bash.ts
+++ b/packages/coding-agent/src/tools/bash.ts
@@ -236,6 +236,7 @@ function formatTimeoutClampNotice(requestedTimeoutSec: number, effectiveTimeoutS
 export class BashTool implements AgentTool<BashToolSchema, BashToolDetails> {
 	readonly name = "bash";
 	readonly label = "Bash";
+	readonly loadMode = "essential";
 	readonly description: string;
 	readonly parameters: BashToolSchema;
 	readonly concurrency = "exclusive";
diff --git a/packages/coding-agent/src/tools/browser.ts b/packages/coding-agent/src/tools/browser.ts
index 08506afdd..d043ab892 100644
--- a/packages/coding-agent/src/tools/browser.ts
+++ b/packages/coding-agent/src/tools/browser.ts
@@ -110,6 +110,8 @@ function resolveBrowserKind(params: BrowserParams, session: ToolSession): Browse
 export class BrowserTool implements AgentTool<typeof browserSchema, BrowserToolDetails> {
 	readonly name = "browser";
 	readonly label = "Browser";
+	readonly loadMode = "discoverable";
+	readonly summary = "Control a headless browser to navigate and interact with web pages";
 	readonly parameters = browserSchema;
 	readonly strict = true;
 
diff --git a/packages/coding-agent/src/tools/calculator.ts b/packages/coding-agent/src/tools/calculator.ts
index 492e13296..2cb5975ad 100644
--- a/packages/coding-agent/src/tools/calculator.ts
+++ b/packages/coding-agent/src/tools/calculator.ts
@@ -396,6 +396,8 @@ type CalculatorParams = Static<typeof calculatorSchema>;
 export class CalculatorTool implements AgentTool<typeof calculatorSchema, CalculatorToolDetails> {
 	readonly name = "calc";
 	readonly label = "Calc";
+	readonly summary = "Evaluate a mathematical expression";
+	readonly loadMode = "discoverable";
 	readonly description: string;
 	readonly parameters = calculatorSchema;
 	readonly strict = true;
diff --git a/packages/coding-agent/src/tools/checkpoint.ts b/packages/coding-agent/src/tools/checkpoint.ts
index 444079482..6ea27c8df 100644
--- a/packages/coding-agent/src/tools/checkpoint.ts
+++ b/packages/coding-agent/src/tools/checkpoint.ts
@@ -49,9 +49,11 @@ function isTopLevelSession(session: ToolSession): boolean {
 export class CheckpointTool implements AgentTool<typeof checkpointSchema, CheckpointToolDetails> {
 	readonly name = "checkpoint";
 	readonly label = "Checkpoint";
+	readonly summary = "Create a git-based checkpoint to save and restore session state";
 	readonly description: string;
 	readonly parameters = checkpointSchema;
 	readonly strict = true;
+	readonly loadMode = "discoverable";
 	readonly intent = (args: Partial<CheckpointParams>) => (args.goal ? `checkpointing: ${args.goal}` : "checkpointing");
 
 	constructor(private readonly session: ToolSession) {
@@ -92,9 +94,11 @@ export class CheckpointTool implements AgentTool<typeof checkpointSchema, Checkp
 export class RewindTool implements AgentTool<typeof rewindSchema, RewindToolDetails> {
 	readonly name = "rewind";
 	readonly label = "Rewind";
+	readonly summary = "Rewind to a previously created checkpoint";
 	readonly description: string;
 	readonly parameters = rewindSchema;
 	readonly strict = true;
+	readonly loadMode = "discoverable";
 	readonly intent = (): string => "rewinding";
 
 	constructor(private readonly session: ToolSession) {
diff --git a/packages/coding-agent/src/tools/debug.ts b/packages/coding-agent/src/tools/debug.ts
index 73519202f..95a558a10 100644
--- a/packages/coding-agent/src/tools/debug.ts
+++ b/packages/coding-agent/src/tools/debug.ts
@@ -597,10 +597,12 @@ export const debugToolRenderer = {
 export class DebugTool implements AgentTool<typeof debugSchema, DebugToolDetails> {
 	readonly name = "debug";
 	readonly label = "Debug";
+	readonly summary = "Debug a running process with DAP (debugger adapter protocol)";
 	readonly description: string;
 	readonly parameters = debugSchema;
 	readonly strict = true;
 	readonly concurrency = "exclusive";
+	readonly loadMode = "discoverable";
 
 	constructor(private readonly session: ToolSession) {
 		this.description = prompt.render(debugDescription);
diff --git a/packages/coding-agent/src/tools/eval.ts b/packages/coding-agent/src/tools/eval.ts
index 500f962ea..bc58a539b 100644
--- a/packages/coding-agent/src/tools/eval.ts
+++ b/packages/coding-agent/src/tools/eval.ts
@@ -207,6 +207,8 @@ async function resolveBackend(
 
 export class EvalTool implements AgentTool<typeof evalSchema> {
 	readonly name = "eval";
+	readonly summary = "Execute Python or JavaScript code in an in-process eval backend";
+	readonly loadMode = "discoverable";
 	readonly label = "Eval";
 	get description(): string {
 		if (!this.session) return getEvalToolDescription();
diff --git a/packages/coding-agent/src/tools/find.ts b/packages/coding-agent/src/tools/find.ts
index 0266b9340..36da5a682 100644
--- a/packages/coding-agent/src/tools/find.ts
+++ b/packages/coding-agent/src/tools/find.ts
@@ -88,6 +88,8 @@ export interface FindToolOptions {
 
 export class FindTool implements AgentTool<typeof findSchema, FindToolDetails> {
 	readonly name = "find";
+	readonly summary = "Find files and directories matching a glob pattern";
+	readonly loadMode = "discoverable";
 	readonly label = "Find";
 	readonly description: string;
 	readonly parameters = findSchema;
diff --git a/packages/coding-agent/src/tools/gh.ts b/packages/coding-agent/src/tools/gh.ts
index 1959ed5c7..b7fe1a21e 100644
--- a/packages/coding-agent/src/tools/gh.ts
+++ b/packages/coding-agent/src/tools/gh.ts
@@ -2087,6 +2087,8 @@ function buildTextResult(
 
 export class GithubTool implements AgentTool<typeof githubSchema, GhToolDetails> {
 	readonly name = "github";
+	readonly summary = "Interact with GitHub issues, pull requests, and repositories";
+	readonly loadMode = "discoverable";
 	readonly label = "GitHub";
 	readonly description = prompt.render(githubDescription);
 	readonly parameters = githubSchema;
diff --git a/packages/coding-agent/src/tools/hindsight-recall.ts b/packages/coding-agent/src/tools/hindsight-recall.ts
index 5f5a60dbb..ca78b0573 100644
--- a/packages/coding-agent/src/tools/hindsight-recall.ts
+++ b/packages/coding-agent/src/tools/hindsight-recall.ts
@@ -19,6 +19,8 @@ export class HindsightRecallTool implements AgentTool<typeof hindsightRecallSche
 	readonly description = recallDescription;
 	readonly parameters = hindsightRecallSchema;
 	readonly strict = true;
+	readonly loadMode = "discoverable";
+	readonly summary = "Search hindsight memory for relevant prior context";
 
 	constructor(private readonly session: ToolSession) {}
 
diff --git a/packages/coding-agent/src/tools/hindsight-reflect.ts b/packages/coding-agent/src/tools/hindsight-reflect.ts
index 732a0f29a..8220c1a10 100644
--- a/packages/coding-agent/src/tools/hindsight-reflect.ts
+++ b/packages/coding-agent/src/tools/hindsight-reflect.ts
@@ -18,6 +18,8 @@ export class HindsightReflectTool implements AgentTool<typeof hindsightReflectSc
 	readonly description = reflectDescription;
 	readonly parameters = hindsightReflectSchema;
 	readonly strict = true;
+	readonly loadMode = "discoverable";
+	readonly summary = "Reflect on recent work and write hindsight memory";
 
 	constructor(private readonly session: ToolSession) {}
 
diff --git a/packages/coding-agent/src/tools/hindsight-retain.ts b/packages/coding-agent/src/tools/hindsight-retain.ts
index 2ea7c55b8..013db55a3 100644
--- a/packages/coding-agent/src/tools/hindsight-retain.ts
+++ b/packages/coding-agent/src/tools/hindsight-retain.ts
@@ -28,6 +28,8 @@ export class HindsightRetainTool implements AgentTool<typeof hindsightRetainSche
 	readonly description = retainDescription;
 	readonly parameters = hindsightRetainSchema;
 	readonly strict = true;
+	readonly loadMode = "discoverable";
+	readonly summary = "Store important facts in hindsight memory";
 
 	constructor(private readonly session: ToolSession) {}
 
diff --git a/packages/coding-agent/src/tools/index.ts b/packages/coding-agent/src/tools/index.ts
index 6e2dcfaa6..b8ab8e5e5 100644
--- a/packages/coding-agent/src/tools/index.ts
+++ b/packages/coding-agent/src/tools/index.ts
@@ -234,22 +234,6 @@ export type ToolFactory = (session: ToolSession) => Tool | null | Promise<Tool |
 
 export type BuiltinToolLoadMode = "essential" | "discoverable";
 
-/** Per-tool discovery metadata for built-ins. Kept separate from BUILTIN_TOOLS so the public
- *  factory map remains directly callable (`BUILTIN_TOOLS.read(session)`). */
-export interface BuiltinToolMetadata {
-	/** "essential" tools are always loaded regardless of discovery mode.
-	 *  "discoverable" tools are hidden behind search_tool_bm25 when tools.discoveryMode === "all". */
-	loadMode: BuiltinToolLoadMode;
-	/** Short one-line summary for the BM25 corpus (optional; falls back to tool description). */
-	summary?: string;
-}
-
-/** @deprecated Internal shape used by older callers. Prefer BUILTIN_TOOLS (factory) +
- *  BUILTIN_TOOL_METADATA (loadMode/summary). */
-export interface BuiltinEntry extends BuiltinToolMetadata {
-	factory: ToolFactory;
-}
-
 /** Default essential tool names when tools.essentialOverride is empty. */
 export const DEFAULT_ESSENTIAL_TOOL_NAMES: readonly string[] = ["read", "bash", "edit"] as const;
 
@@ -262,7 +246,7 @@ export function computeEssentialBuiltinNames(settings: Settings): string[] {
 	const override = settings.get("tools.essentialOverride") ?? [];
 	const cleaned = override.map(name => name.trim()).filter(Boolean);
 	if (cleaned.length > 0) {
-		return cleaned.filter(name => name in BUILTIN_TOOL_METADATA);
+		return cleaned.filter(name => name in BUILTIN_TOOLS);
 	}
 	return [...DEFAULT_ESSENTIAL_TOOL_NAMES];
 }
@@ -305,57 +289,6 @@ export const BUILTIN_TOOLS: Record<string, ToolFactory> = {
 	reflect: HindsightReflectTool.createIf,
 };
 
-/**
- * Per-tool discovery metadata. Keys must align with BUILTIN_TOOLS. Used by initial-tool filtering
- * (sdk.ts) and discovery-corpus collection (search-tool-bm25). Kept separate so the public
- * BUILTIN_TOOLS map remains a directly callable factory record.
- */
-export const BUILTIN_TOOL_METADATA: Record<string, BuiltinToolMetadata> = {
-	read: { loadMode: "essential" },
-	bash: { loadMode: "essential" },
-	edit: { loadMode: "essential" },
-	ast_grep: { loadMode: "discoverable", summary: "Search code with AST patterns (structural grep)" },
-	ast_edit: { loadMode: "discoverable", summary: "Perform AST-aware code edits (structural refactoring)" },
-	render_mermaid: { loadMode: "discoverable", summary: "Render a Mermaid diagram to an image" },
-	ask: { loadMode: "discoverable", summary: "Ask the user a clarifying question" },
-	debug: { loadMode: "discoverable", summary: "Debug a running process with DAP (debugger adapter protocol)" },
-	eval: { loadMode: "discoverable", summary: "Execute Python or JavaScript code in an in-process eval backend" },
-	calc: { loadMode: "discoverable", summary: "Evaluate a mathematical expression" },
-	ssh: { loadMode: "discoverable", summary: "Execute a command on a remote host over SSH" },
-	github: { loadMode: "discoverable", summary: "Interact with GitHub issues, pull requests, and repositories" },
-	find: { loadMode: "discoverable", summary: "Find files and directories matching a glob pattern" },
-	search: { loadMode: "discoverable", summary: "Search file contents using ripgrep (fast text search)" },
-	lsp: {
-		loadMode: "discoverable",
-		summary: "Query LSP (language server) for diagnostics, hover info, and references",
-	},
-	notebook: { loadMode: "discoverable", summary: "Read and execute Jupyter notebooks" },
-	inspect_image: { loadMode: "discoverable", summary: "Describe or analyze an image file" },
-	browser: {
-		loadMode: "discoverable",
-		summary: "Control a headless browser to navigate and interact with web pages",
-	},
-	checkpoint: {
-		loadMode: "discoverable",
-		summary: "Create a git-based checkpoint to save and restore session state",
-	},
-	rewind: { loadMode: "discoverable", summary: "Rewind to a previously created checkpoint" },
-	task: { loadMode: "discoverable", summary: "Spawn a subagent to complete a parallel task" },
-	job: { loadMode: "discoverable", summary: "Manage long-running background jobs (async bash/python)" },
-	recipe: { loadMode: "discoverable", summary: "Execute a saved bash recipe (multi-step shell command preset)" },
-	irc: { loadMode: "discoverable", summary: "Send and receive messages between agents over IRC-like channels" },
-	todo_write: {
-		loadMode: "discoverable",
-		summary: "Write a structured todo list to track progress within a session",
-	},
-	web_search: { loadMode: "discoverable", summary: "Search the web for up-to-date information" },
-	search_tool_bm25: { loadMode: "essential" },
-	write: { loadMode: "discoverable", summary: "Write content to a file (creates or overwrites)" },
-	retain: { loadMode: "discoverable", summary: "Store important facts in hindsight memory" },
-	recall: { loadMode: "discoverable", summary: "Search hindsight memory for relevant prior context" },
-	reflect: { loadMode: "discoverable", summary: "Reflect on recent work and write hindsight memory" },
-};
-
 export const HIDDEN_TOOLS: Record<string, ToolFactory> = {
 	yield: s => new YieldTool(s),
 	report_finding: () => reportFindingTool,
@@ -371,32 +304,6 @@ export interface EvalBackendsAllowance {
 	js: boolean;
 }
 
-/**
- * Return all built-in tools whose metadata `loadMode` is "discoverable".
- * Used by search_tool_bm25 to build the BM25 corpus when tools.discoveryMode === "all".
- * Pass an optional exclusion set to filter out names that are already active.
- */
-export function getBuiltinDiscoverableEntries(
-	excludeNames?: ReadonlySet<string>,
-): Array<{ name: string; entry: BuiltinEntry }> {
-	return Object.entries(BUILTIN_TOOL_METADATA)
-		.filter(([name, meta]) => meta.loadMode === "discoverable" && !excludeNames?.has(name))
-		.map(([name, meta]) => {
-			const factory = BUILTIN_TOOLS[name];
-			if (!factory) {
-				throw new Error(`BUILTIN_TOOL_METADATA["${name}"] has no matching factory in BUILTIN_TOOLS`);
-			}
-			return { name, entry: { factory, ...meta } satisfies BuiltinEntry };
-		});
-}
-
-/** Names of all built-ins whose metadata `loadMode` is "discoverable". */
-export function getBuiltinDiscoverableNames(): string[] {
-	return Object.entries(BUILTIN_TOOL_METADATA)
-		.filter(([, meta]) => meta.loadMode === "discoverable")
-		.map(([name]) => name);
-}
-
 /**
  * Parse PI_PY / PI_JS environment variables. Each is a boolean flag; unset
  * means "not specified, defer to settings". Returns null when neither is set
diff --git a/packages/coding-agent/src/tools/inspect-image.ts b/packages/coding-agent/src/tools/inspect-image.ts
index dc956140c..055ef66dd 100644
--- a/packages/coding-agent/src/tools/inspect-image.ts
+++ b/packages/coding-agent/src/tools/inspect-image.ts
@@ -41,6 +41,8 @@ function extractResponseText(message: AssistantMessage): string {
 export class InspectImageTool implements AgentTool<typeof inspectImageSchema, InspectImageToolDetails> {
 	readonly name = "inspect_image";
 	readonly label = "InspectImage";
+	readonly loadMode = "discoverable";
+	readonly summary = "Describe or analyze an image file";
 	readonly description: string;
 	readonly parameters = inspectImageSchema;
 	readonly strict = false;
diff --git a/packages/coding-agent/src/tools/irc.ts b/packages/coding-agent/src/tools/irc.ts
index b01487774..688f52e86 100644
--- a/packages/coding-agent/src/tools/irc.ts
+++ b/packages/coding-agent/src/tools/irc.ts
@@ -74,10 +74,11 @@ export interface IrcDetails {
 export class IrcTool implements AgentTool<typeof ircSchema, IrcDetails> {
 	readonly name = "irc";
 	readonly label = "IRC";
+	readonly summary = "Send and receive messages between agents over IRC-like channels";
 	readonly description: string;
 	readonly parameters = ircSchema;
 	readonly strict = true;
-
+	readonly loadMode = "discoverable";
 	constructor(private readonly session: ToolSession) {
 		this.description = prompt.render(ircDescription);
 	}
diff --git a/packages/coding-agent/src/tools/job.ts b/packages/coding-agent/src/tools/job.ts
index 3973228ee..d40c00ebf 100644
--- a/packages/coding-agent/src/tools/job.ts
+++ b/packages/coding-agent/src/tools/job.ts
@@ -76,10 +76,11 @@ export interface JobToolDetails {
 export class JobTool implements AgentTool<typeof jobSchema, JobToolDetails> {
 	readonly name = "job";
 	readonly label = "Job";
+	readonly summary = "Manage long-running background jobs (async bash/python)";
 	readonly description: string;
 	readonly parameters = jobSchema;
 	readonly strict = true;
-
+	readonly loadMode = "discoverable";
 	constructor(private readonly session: ToolSession) {
 		this.description = prompt.render(jobDescription);
 	}
diff --git a/packages/coding-agent/src/tools/notebook.ts b/packages/coding-agent/src/tools/notebook.ts
index 00eb31e67..77be1ef00 100644
--- a/packages/coding-agent/src/tools/notebook.ts
+++ b/packages/coding-agent/src/tools/notebook.ts
@@ -64,6 +64,8 @@ type NotebookParams = Static<typeof notebookSchema>;
 export class NotebookTool implements AgentTool<typeof notebookSchema, NotebookToolDetails> {
 	readonly name = "notebook";
 	readonly label = "Notebook";
+	readonly loadMode = "discoverable";
+	readonly summary = "Read and execute Jupyter notebooks";
 	readonly description = "Edit, insert, or delete cells in Jupyter notebooks (.ipynb). cell_index is 0-based.";
 	readonly parameters = notebookSchema;
 	readonly strict = true;
diff --git a/packages/coding-agent/src/tools/read.ts b/packages/coding-agent/src/tools/read.ts
index 913d86b16..0fe9cad79 100644
--- a/packages/coding-agent/src/tools/read.ts
+++ b/packages/coding-agent/src/tools/read.ts
@@ -512,6 +512,7 @@ interface ResolvedSqliteReadPath {
 export class ReadTool implements AgentTool<typeof readSchema, ReadToolDetails> {
 	readonly name = "read";
 	readonly label = "Read";
+	readonly loadMode = "essential";
 	readonly description: string;
 	readonly parameters = readSchema;
 	readonly nonAbortable = true;
diff --git a/packages/coding-agent/src/tools/recipe/index.ts b/packages/coding-agent/src/tools/recipe/index.ts
index 8b3b7e777..70332b04c 100644
--- a/packages/coding-agent/src/tools/recipe/index.ts
+++ b/packages/coding-agent/src/tools/recipe/index.ts
@@ -33,6 +33,8 @@ export class RecipeTool implements AgentTool<typeof recipeSchema, BashToolDetail
 	readonly parameters = recipeSchema;
 	readonly strict = true;
 	readonly concurrency = "exclusive";
+	readonly loadMode = "discoverable";
+	readonly summary = "Execute a saved bash recipe (multi-step shell command preset)";
 	readonly mergeCallAndResult = true;
 	readonly inline = true;
 	readonly renderCall: (args: RecipeRenderArgs, options: RenderResultOptions, uiTheme: Theme) => Component;
diff --git a/packages/coding-agent/src/tools/render-mermaid.ts b/packages/coding-agent/src/tools/render-mermaid.ts
index ca029a493..38d89a883 100644
--- a/packages/coding-agent/src/tools/render-mermaid.ts
+++ b/packages/coding-agent/src/tools/render-mermaid.ts
@@ -35,9 +35,11 @@ export interface RenderMermaidToolDetails {
 export class RenderMermaidTool implements AgentTool<typeof renderMermaidSchema, RenderMermaidToolDetails> {
 	readonly name = "render_mermaid";
 	readonly label = "RenderMermaid";
+	readonly summary = "Render a Mermaid diagram to an image";
 	readonly description: string;
 	readonly parameters = renderMermaidSchema;
 	readonly strict = true;
+	readonly loadMode = "discoverable";
 
 	constructor(private readonly session: ToolSession) {
 		this.description = prompt.render(renderMermaidDescription);
diff --git a/packages/coding-agent/src/tools/search-tool-bm25.ts b/packages/coding-agent/src/tools/search-tool-bm25.ts
index 3d2607e23..bbf735a04 100644
--- a/packages/coding-agent/src/tools/search-tool-bm25.ts
+++ b/packages/coding-agent/src/tools/search-tool-bm25.ts
@@ -210,6 +210,7 @@ function renderFallbackResult(text: string, theme: Theme): Component {
 export class SearchToolBm25Tool implements AgentTool<typeof searchToolBm25Schema, SearchToolBm25Details> {
 	readonly name = "search_tool_bm25";
 	readonly label = "SearchTools";
+	readonly loadMode = "essential";
 	get description(): string {
 		return renderSearchToolBm25Description(getDiscoverableToolsForDescription(this.session));
 	}
diff --git a/packages/coding-agent/src/tools/search.ts b/packages/coding-agent/src/tools/search.ts
index baacdbc5b..ba72f810c 100644
--- a/packages/coding-agent/src/tools/search.ts
+++ b/packages/coding-agent/src/tools/search.ts
@@ -80,6 +80,8 @@ type SearchParams = Static<typeof searchSchema>;
 export class SearchTool implements AgentTool<typeof searchSchema, SearchToolDetails> {
 	readonly name = "search";
 	readonly label = "Search";
+	readonly loadMode = "discoverable";
+	readonly summary = "Search file contents using ripgrep (fast text search)";
 	readonly description: string;
 	readonly parameters = searchSchema;
 	readonly strict = true;
diff --git a/packages/coding-agent/src/tools/ssh.ts b/packages/coding-agent/src/tools/ssh.ts
index 1b88a2c00..8175c15a1 100644
--- a/packages/coding-agent/src/tools/ssh.ts
+++ b/packages/coding-agent/src/tools/ssh.ts
@@ -120,6 +120,8 @@ type SshToolParams = Static<typeof sshSchema>;
 
 export class SshTool implements AgentTool<typeof sshSchema, SSHToolDetails> {
 	readonly name = "ssh";
+	readonly summary = "Execute a command on a remote host over SSH";
+	readonly loadMode = "discoverable";
 	readonly label = "SSH";
 	readonly parameters = sshSchema;
 	readonly concurrency = "exclusive";
diff --git a/packages/coding-agent/src/tools/todo-write.ts b/packages/coding-agent/src/tools/todo-write.ts
index 264b006e3..05b953322 100644
--- a/packages/coding-agent/src/tools/todo-write.ts
+++ b/packages/coding-agent/src/tools/todo-write.ts
@@ -503,11 +503,12 @@ function formatSummary(phases: TodoPhase[], errors: string[]): string {
 export class TodoWriteTool implements AgentTool<typeof todoWriteSchema, TodoWriteToolDetails> {
 	readonly name = "todo_write";
 	readonly label = "Todo Write";
+	readonly summary = "Write a structured todo list to track progress within a session";
 	readonly description: string;
 	readonly parameters = todoWriteSchema;
 	readonly concurrency = "exclusive";
 	readonly strict = true;
-
+	readonly loadMode = "discoverable";
 	constructor(private readonly session: ToolSession) {
 		this.description = prompt.render(todoWriteDescription);
 	}
diff --git a/packages/coding-agent/src/tools/write.ts b/packages/coding-agent/src/tools/write.ts
index a494a09b4..974f1d31c 100644
--- a/packages/coding-agent/src/tools/write.ts
+++ b/packages/coding-agent/src/tools/write.ts
@@ -166,6 +166,8 @@ export class WriteTool implements AgentTool<typeof writeSchema, WriteToolDetails
 	readonly nonAbortable = true;
 	readonly strict = true;
 	readonly concurrency = "exclusive";
+	readonly loadMode = "discoverable";
+	readonly summary = "Write content to a file (creates or overwrites)";
 
 	readonly #writethrough: WritethroughCallback;
 
diff --git a/packages/coding-agent/src/web/search/index.ts b/packages/coding-agent/src/web/search/index.ts
index a1e1950b7..35a720876 100644
--- a/packages/coding-agent/src/web/search/index.ts
+++ b/packages/coding-agent/src/web/search/index.ts
@@ -211,6 +211,8 @@ export class WebSearchTool implements AgentTool<typeof webSearchSchema, SearchRe
 	readonly description: string;
 	readonly parameters = webSearchSchema;
 	readonly strict = true;
+	readonly loadMode = "discoverable";
+	readonly summary = "Search the web for up-to-date information";
 
 	constructor(_session: ToolSession) {
 		this.description = prompt.render(webSearchDescription);
diff --git a/packages/coding-agent/test/agent-session-manual-retry.test.ts b/packages/coding-agent/test/agent-session-manual-retry.test.ts
index 485a894a0..abb3f3b2e 100644
--- a/packages/coding-agent/test/agent-session-manual-retry.test.ts
+++ b/packages/coding-agent/test/agent-session-manual-retry.test.ts
@@ -52,6 +52,7 @@ describe("AgentSession manual retry", () => {
 	beforeEach(async () => {
 		tempDir = TempDir.createSync("@pi-manual-retry-");
 		authStorage = await AuthStorage.create(path.join(tempDir.path(), "testauth.db"));
+		authStorage.setRuntimeApiKey("anthropic", "test-key");
 	});
 
 	afterEach(async () => {
diff --git a/packages/coding-agent/test/agent-session-mcp-discovery.test.ts b/packages/coding-agent/test/agent-session-mcp-discovery.test.ts
index b63d19840..55965a57d 100644
--- a/packages/coding-agent/test/agent-session-mcp-discovery.test.ts
+++ b/packages/coding-agent/test/agent-session-mcp-discovery.test.ts
@@ -915,7 +915,10 @@ describe("AgentSession MCP discovery", () => {
 	// ── Findings #4: built-in discovery is restricted to declared discoverable ─
 	it("getDiscoverableTools({source:'builtin'}) excludes hidden and non-declared registry tools", () => {
 		const readTool = createBasicTool("read", "Read");
+		readTool.loadMode = "essential";
 		const findTool = createBasicTool("find", "Find");
+		findTool.loadMode = "discoverable";
+		findTool.summary = "Find files and directories matching a glob pattern";
 		const resolveTool = createBasicTool("resolve", "Resolve"); // hidden — must be excluded
 		const customTool = createBasicTool("custom_inactive", "Custom"); // not in metadata — must be excluded
 		const toolRegistry = new Map([
@@ -942,7 +945,7 @@ describe("AgentSession MCP discovery", () => {
 		const names = builtin.map(t => t.name);
 		expect(names).toContain("find"); // declared discoverable AND present in registry
 		expect(names).not.toContain("read"); // already active
-		expect(names).not.toContain("resolve"); // hidden — not in BUILTIN_TOOL_METADATA
-		expect(names).not.toContain("custom_inactive"); // unknown — not in BUILTIN_TOOL_METADATA
+		expect(names).not.toContain("resolve"); // hidden — no discoverable loadMode
+		expect(names).not.toContain("custom_inactive"); // unknown — no discoverable loadMode
 	});
 });
diff --git a/packages/coding-agent/test/tool-discovery/initial-tools.test.ts b/packages/coding-agent/test/tool-discovery/initial-tools.test.ts
index 5cd4ba7ce..c1af11c88 100644
--- a/packages/coding-agent/test/tool-discovery/initial-tools.test.ts
+++ b/packages/coding-agent/test/tool-discovery/initial-tools.test.ts
@@ -1,12 +1,65 @@
 import { describe, expect, it } from "bun:test";
 import { Settings } from "../../src/config/settings";
+import type { ToolSession } from "../../src/tools/index";
 import {
-	BUILTIN_TOOL_METADATA,
+	AskTool,
 	BUILTIN_TOOLS,
 	computeEssentialBuiltinNames,
+	createTools,
 	DEFAULT_ESSENTIAL_TOOL_NAMES,
+	IrcTool,
+	JobTool,
+	RecipeTool,
+	SshTool,
 } from "../../src/tools/index";
 
+const allToolsSettings = Settings.isolated({
+	"astGrep.enabled": true,
+	"astEdit.enabled": true,
+	"renderMermaid.enabled": true,
+	"debug.enabled": true,
+	"find.enabled": true,
+	"search.enabled": true,
+	"github.enabled": true,
+	"lsp.enabled": true,
+	"notebook.enabled": true,
+	"inspect_image.enabled": true,
+	"web_search.enabled": true,
+	"calc.enabled": true,
+	"browser.enabled": true,
+	"checkpoint.enabled": true,
+	"irc.enabled": true,
+	"recipe.enabled": true,
+	"todo.enabled": true,
+	"memory.backend": "hindsight",
+	"tools.discoveryMode": "all",
+});
+
+const toolSession: ToolSession = {
+	cwd: "/tmp/test",
+	hasUI: false,
+	getSessionFile: () => null,
+	getSessionSpawns: () => null,
+	settings: allToolsSettings,
+	isToolDiscoveryEnabled: () => true,
+	getSelectedDiscoveredToolNames: () => [],
+	activateDiscoveredTools: async names => names,
+};
+
+async function getToolMetadata(): Promise<Map<string, { loadMode?: string; summary?: string }>> {
+	const tools = await createTools(toolSession, Object.keys(BUILTIN_TOOLS));
+	const metadata = new Map(tools.map(tool => [tool.name, { loadMode: tool.loadMode, summary: tool.summary }]));
+	for (const tool of [
+		new AskTool({ ...toolSession, hasUI: true }),
+		new SshTool(toolSession, [], new Map(), ""),
+		new JobTool(toolSession),
+		new RecipeTool(toolSession, []),
+		new IrcTool(toolSession),
+	]) {
+		metadata.set(tool.name, { loadMode: tool.loadMode, summary: tool.summary });
+	}
+	return metadata;
+}
 describe("BUILTIN_TOOLS public factory map", () => {
 	it("exposes callable tool factories (back-compat for external SDK callers)", () => {
 		// External callers may invoke BUILTIN_TOOLS.read(session) directly. Verify the value
@@ -16,31 +69,23 @@ describe("BUILTIN_TOOLS public factory map", () => {
 		expect(typeof BUILTIN_TOOLS.edit).toBe("function");
 	});
 
-	it("has a callable factory for every metadata entry", () => {
-		for (const name of Object.keys(BUILTIN_TOOL_METADATA)) {
-			expect(typeof BUILTIN_TOOLS[name]).toBe("function");
-		}
-	});
-
-	it("has metadata for every factory entry", () => {
-		for (const name of Object.keys(BUILTIN_TOOLS)) {
-			expect(BUILTIN_TOOL_METADATA[name]).toBeDefined();
-		}
+	it("sets loading fields on tool definitions without wrapping factories", async () => {
+		const metadata = await getToolMetadata();
+		const missing = Object.keys(BUILTIN_TOOLS).filter(name => metadata.get(name)?.loadMode === undefined);
+		expect(missing).toEqual([]);
 	});
 });
 
-describe("BUILTIN_TOOL_METADATA loadMode annotations", () => {
-	it("marks read, bash, edit as essential", () => {
-		expect(BUILTIN_TOOL_METADATA.read?.loadMode).toBe("essential");
-		expect(BUILTIN_TOOL_METADATA.bash?.loadMode).toBe("essential");
-		expect(BUILTIN_TOOL_METADATA.edit?.loadMode).toBe("essential");
+describe("built-in tool loadMode annotations", () => {
+	it("marks read, bash, edit, and search_tool_bm25 as essential", async () => {
+		const metadata = await getToolMetadata();
+		expect(metadata.get("read")?.loadMode).toBe("essential");
+		expect(metadata.get("bash")?.loadMode).toBe("essential");
+		expect(metadata.get("edit")?.loadMode).toBe("essential");
+		expect(metadata.get("search_tool_bm25")?.loadMode).toBe("essential");
 	});
 
-	it("marks search_tool_bm25 as essential (discovery tool itself)", () => {
-		expect(BUILTIN_TOOL_METADATA.search_tool_bm25?.loadMode).toBe("essential");
-	});
-
-	it("marks non-essential tools as discoverable", () => {
+	it("marks non-essential tools as discoverable", async () => {
 		const discoverableExpected = [
 			"ast_grep",
 			"ast_edit",
@@ -70,14 +115,15 @@ describe("BUILTIN_TOOL_METADATA loadMode annotations", () => {
 			"recall",
 			"reflect",
 		];
-		for (const name of discoverableExpected) {
-			expect(BUILTIN_TOOL_METADATA[name]?.loadMode).toBe("discoverable");
-		}
+		const metadata = await getToolMetadata();
+		const missing = discoverableExpected.filter(name => metadata.get(name)?.loadMode !== "discoverable");
+		expect(missing).toEqual([]);
 	});
 
-	it("provides a summary for every discoverable tool", () => {
+	it("provides a summary for every discoverable tool", async () => {
 		const missing: string[] = [];
-		for (const [name, meta] of Object.entries(BUILTIN_TOOL_METADATA)) {
+		const metadata = await getToolMetadata();
+		for (const [name, meta] of metadata) {
 			if (meta.loadMode === "discoverable" && !meta.summary) {
 				missing.push(name);
 			}