feat(coding-agent): simplified skill management by removing per-task pinning

- Removed per-task skill pinning feature; subagents now inherit session skill set instead of per-task selection. - Removed `preloadedSkills` option from `CreateAgentSessionOptions` interface and related system prompt plumbing. - Removed `skills` field from Task schema; task execution now passes available session skills directly to subagents. - Simplified task execution pipeline by removing skill resolution logic and preloaded skills handling from system prompt templates.
2026-02-26 20:47:54 +01:00
parent e4bd646255
commit 2e20d87151
13 changed files with 29 additions and 143 deletions
@@ -122,19 +122,12 @@ For providers other than codex/claude/native (for example `agents`, `claude-plug

 System prompt construction (`src/system-prompt.ts`) uses discovered skills as follows:

- if `read` tool is available **and** no explicit preloaded skills are supplied:
+- if `read` tool is available:
  - include discovered skills list in prompt
 - otherwise:
  - omit discovered list
- if preloaded skills are provided (for example from Task tool skill pinning):
-  - inline full preloaded skill contents in `<preloaded_skills>`

-### Task tool skill pinning
-
-When a Task call specifies `skills`, runtime resolves names against session skills:
-
- unknown names cause an immediate error with available skill names
- resolved skills are passed as preloaded skills to subagents
+Task tool subagents receive the session's discovered/provided skills list via normal session creation; there is no per-task skill pinning override.

 ### Interactive `/skill:<name>` commands

@@ -1,6 +1,20 @@
 # Changelog

 ## [Unreleased]
+### Breaking Changes
+
+- Removed `preloadedSkills` option from `CreateAgentSessionOptions`; skills are no longer inlined into system prompts
+- Removed `skills` field from Task schema; subagents now always inherit the session skill set instead of per-task skill selection
+- Removed Task tool per-task `tasks[].skills` support; subagents now always inherit the session skill set
+- Removed `preloadedSkills` system prompt plumbing and template sections; skills are no longer inlined as a separate preloaded block
+
+### Changed
+
+- Simplified task execution to always pass available session skills to subagents instead of resolving per-task skill lists
+
+### Removed
+
+- Removed preloaded skills section from system prompt templates; skills are now referenced only as available resources

 ## [13.3.6] - 2026-02-26
 ### Breaking Changes
@@ -40,16 +40,6 @@ If a skill covers your output, you **MUST** read `skill://<name>` before proceed
 {{/list}}
 </skills>
 {{/if}}
-{{#if preloadedSkills.length}}
-Following skills are preloaded in full; you **MUST** apply instructions directly.
-<preloaded-skills>
-{{#list preloadedSkills join="\n"}}
-<skill name="{{name}}">
-{{content}}
-</skill>
-{{/list}}
-</preloaded-skills>
-{{/if}}
 {{#if rules.length}}
 Rules are local constraints.
 You **MUST** read `rule://<name>` when working in that domain.
@@ -93,14 +93,6 @@ You **MUST** use the following skills, to save you time, when working in their d
 {{/each}}
 {{/if}}

-{{#if preloadedSkills.length}}
-Preloaded skills:
-{{#each preloadedSkills}}
-## {{name}}
-{{content}}
-{{/each}}
-{{/if}}
-
 {{#if rules.length}}
 # Rules
 Domain-specific rules from past experience. **MUST** read `rule://<name>` when working in their territory.
@@ -12,7 +12,6 @@ Subagents lack your conversation history. Every decision, file content, and user
  - `.id`: CamelCase, max 32 chars
  - `.description`: UI display only — subagent never sees it
  - `.assignment`: Complete self-contained instructions. One-liners PROHIBITED; missing acceptance criteria = too vague.
-  - `.skills`: Skill names to preload
 - `context`: Shared background prepended to every assignment. Session-specific info only.
 - `schema`: JTD schema for expected output. Format lives here — **MUST NOT** be duplicated in assignments.
 - `tasks`: Tasks to execute in parallel.
@@ -144,8 +144,6 @@ export interface CreateAgentSessionOptions {

 	/** Skills. Default: discovered from multiple locations */
 	skills?: Skill[];
-	/** Skills to inline into the system prompt instead of listing available skills. */
-	preloadedSkills?: Skill[];
 	/** Rules. Default: discovered from multiple locations */
 	rules?: Rule[];
 	/** Context files (AGENTS.md content). Default: discovered walking up from cwd */
@@ -1128,7 +1126,6 @@ export async function createAgentSession(options: CreateAgentSessionOptions = {}
 		const defaultPrompt = await buildSystemPromptInternal({
 			cwd,
 			skills,
-			preloadedSkills: options.preloadedSkills,
 			contextFiles,
 			tools,
 			toolNames,
@@ -1147,7 +1144,6 @@ export async function createAgentSession(options: CreateAgentSessionOptions = {}
 			return await buildSystemPromptInternal({
 				cwd,
 				skills,
-				preloadedSkills: options.preloadedSkills,
 				contextFiles,
 				tools,
 				toolNames,
@@ -16,24 +16,6 @@ import { loadSkills, type Skill } from "./extensibility/skills";
 import customSystemPromptTemplate from "./prompts/system/custom-system-prompt.md" with { type: "text" };
 import systemPromptTemplate from "./prompts/system/system-prompt.md" with { type: "text" };

-type PreloadedSkill = { name: string; content: string };
-
-async function loadPreloadedSkillContents(preloadedSkills: Skill[]): Promise<PreloadedSkill[]> {
-	const contents = await Promise.all(
-		preloadedSkills.map(async skill => {
-			try {
-				const content = await Bun.file(skill.filePath).text();
-				return { name: skill.name, content };
-			} catch (err) {
-				const message = err instanceof Error ? err.message : String(err);
-				throw new Error(`Failed to load skill "${skill.name}" from ${skill.filePath}: ${message}`);
-			}
-		}),
-	);
-
-	return contents;
-}
-
 function firstNonEmpty(...values: (string | undefined | null)[]): string | null {
 	for (const value of values) {
 		const trimmed = value?.trim();
@@ -350,11 +332,9 @@ export interface BuildSystemPromptOptions {
 	cwd?: string;
 	/** Pre-loaded context files (skips discovery if provided). */
 	contextFiles?: Array<{ path: string; content: string; depth?: number }>;
-	/** Pre-loaded skills (skips discovery if provided). */
+	/** Skills provided directly to system prompt construction. */
 	skills?: Skill[];
-	/** Skills to inline into the system prompt instead of listing available skills. */
-	preloadedSkills?: Skill[];
-	/** Pre-loaded rulebook rules (rules with descriptions, excluding TTSR and always-apply). */
+	/** Pre-loaded rulebook rules (descriptions, excluding TTSR and always-apply). */
 	rules?: Array<{ name: string; description?: string; path: string; globs?: string[] }>;
 	/** Intent field name injected into every tool schema. If set, explains the field in the prompt. */
 	intentField?: string;
@@ -378,13 +358,11 @@ export async function buildSystemPrompt(options: BuildSystemPromptOptions = {}):
 		cwd,
 		contextFiles: providedContextFiles,
 		skills: providedSkills,
-		preloadedSkills: providedPreloadedSkills,
 		rules,
 		intentField,
 		eagerTasks = false,
 	} = options;
 	const resolvedCwd = cwd ?? getProjectDir();
-	const preloadedSkills = providedPreloadedSkills;

 	const prepPromise = (() => {
 		const systemPromptCustomizationPromise = logger.timeAsync("loadSystemPromptFiles", loadSystemPromptFiles, {
@@ -400,9 +378,6 @@ export async function buildSystemPrompt(options: BuildSystemPromptOptions = {}):
 				: skillsSettings?.enabled !== false
 					? loadSkills({ ...skillsSettings, cwd: resolvedCwd }).then(result => result.skills)
 					: Promise.resolve([]);
-		const preloadedSkillContentsPromise = preloadedSkills
-			? logger.timeAsync("loadPreloadedSkills", loadPreloadedSkillContents, preloadedSkills)
-			: [];

 		return Promise.all([
 			resolvePromptInput(customPrompt, "system prompt"),
@@ -411,7 +386,6 @@ export async function buildSystemPrompt(options: BuildSystemPromptOptions = {}):
 			contextFilesPromise,
 			agentsMdSearchPromise,
 			skillsPromise,
-			preloadedSkillContentsPromise,
 		]).then(
 			([
 				resolvedCustomPrompt,
@@ -420,7 +394,6 @@ export async function buildSystemPrompt(options: BuildSystemPromptOptions = {}):
 				contextFiles,
 				agentsMdSearch,
 				skills,
-				preloadedSkillContents,
 			]) => ({
 				resolvedCustomPrompt,
 				resolvedAppendPrompt,
@@ -428,7 +401,6 @@ export async function buildSystemPrompt(options: BuildSystemPromptOptions = {}):
 				contextFiles,
 				agentsMdSearch,
 				skills,
-				preloadedSkillContents,
 			}),
 		);
 	})();
@@ -451,7 +423,6 @@ export async function buildSystemPrompt(options: BuildSystemPromptOptions = {}):
 		files: [],
 	};
 	let skills: Skill[] = providedSkills ?? [];
-	let preloadedSkillContents: PreloadedSkill[] = [];

 	if (prepResult.type === "timeout") {
 		logger.warn("System prompt preparation timed out; using minimal startup context", {
@@ -474,7 +445,6 @@ export async function buildSystemPrompt(options: BuildSystemPromptOptions = {}):
 		contextFiles = prepResult.value.contextFiles;
 		agentsMdSearch = prepResult.value.agentsMdSearch;
 		skills = prepResult.value.skills;
-		preloadedSkillContents = prepResult.value.preloadedSkillContents;
 	}

 	const now = new Date();
@@ -517,7 +487,7 @@ export async function buildSystemPrompt(options: BuildSystemPromptOptions = {}):

 	// Filter skills to only include those with read tool
 	const hasRead = tools?.has("read");
-	const filteredSkills = preloadedSkills === undefined && hasRead ? skills : [];
+	const filteredSkills = hasRead ? skills : [];

 	const environment = await logger.timeAsync("getEnvironmentInfo", getEnvironmentInfo);
 	const data = {
@@ -531,7 +501,6 @@ export async function buildSystemPrompt(options: BuildSystemPromptOptions = {}):
 		contextFiles,
 		agentsMdSearch,
 		skills: filteredSkills,
-		preloadedSkills: preloadedSkillContents,
 		rules: rules ?? [],
 		date,
 		dateTime,
@@ -158,7 +158,6 @@ export interface ExecutorOptions {
 	eventBus?: EventBus;
 	contextFiles?: ContextFileEntry[];
 	skills?: Skill[];
-	preloadedSkills?: Skill[];
 	promptTemplates?: PromptTemplate[];
 	mcpManager?: MCPManager;
 	authStorage?: AuthStorage;
@@ -950,7 +949,6 @@ export async function runSubprocess(options: ExecutorOptions): Promise<SingleRes
 				requireSubmitResultTool: true,
 				contextFiles: options.contextFiles,
 				skills: options.skills,
-				preloadedSkills: options.preloadedSkills,
 				promptTemplates: options.promptTemplates,
 				systemPrompt: defaultPrompt =>
 					renderPromptTemplate(subagentSystemPromptTemplate, {
@@ -690,58 +690,13 @@ export class TaskTool implements AgentTool<TaskSchema, TaskToolDetails, Theme> {

 			// Build full prompts with context prepended
 			const tasksWithContext = tasksWithUniqueIds.map(t => renderTemplate(context, t));
+			const availableSkills = [...(this.session.skills ?? [])];
 			const contextFiles = this.session.contextFiles;
-			const availableSkills = this.session.skills;
-			const availableSkillList = availableSkills ?? [];
 			const promptTemplates = this.session.promptTemplates;
-			const skillLookup = new Map(availableSkillList.map(skill => [skill.name, skill]));
-			const missingSkillsByTask: Array<{ id: string; missing: string[] }> = [];
-			const tasksWithSkills = tasksWithContext.map(task => {
-				if (task.skills === undefined) {
-					return { ...task, resolvedSkills: availableSkills, preloadedSkills: undefined };
-				}
-				const requested = task.skills;
-				const resolved = [] as typeof availableSkillList;
-				const missing: string[] = [];
-				const seen = new Set<string>();
-				for (const name of requested) {
-					const trimmed = name.trim();
-					if (!trimmed || seen.has(trimmed)) continue;
-					seen.add(trimmed);
-					const skill = skillLookup.get(trimmed);
-					if (skill) {
-						resolved.push(skill);
-					} else {
-						missing.push(trimmed);
-					}
-				}
-				if (missing.length > 0) {
-					missingSkillsByTask.push({ id: task.id, missing });
-				}
-				return { ...task, resolvedSkills: resolved, preloadedSkills: resolved };
-			});
-
-			if (missingSkillsByTask.length > 0) {
-				const available = availableSkillList.map(skill => skill.name).join(", ") || "none";
-				const details = missingSkillsByTask.map(entry => `${entry.id}: ${entry.missing.join(", ")}`).join("; ");
-				return {
-					content: [
-						{
-							type: "text",
-							text: `Unknown skills requested: ${details}. Available skills: ${available}`,
-						},
-					],
-					details: {
-						projectAgentsDir,
-						results: [],
-						totalDurationMs: Date.now() - startTime,
-					},
-				};
-			}

 			// Initialize progress for all tasks
-			for (let i = 0; i < tasksWithSkills.length; i++) {
-				const t = tasksWithSkills[i];
+			for (let i = 0; i < tasksWithContext.length; i++) {
+				const t = tasksWithContext[i];
 				progressMap.set(i, {
 					index: i,
 					id: t.id,
@@ -760,7 +715,7 @@ export class TaskTool implements AgentTool<TaskSchema, TaskToolDetails, Theme> {
 			}
 			emitProgress();

-			const runTask = async (task: (typeof tasksWithSkills)[number], index: number) => {
+			const runTask = async (task: (typeof tasksWithContext)[number], index: number) => {
 				if (!isIsolated) {
 					return runSubprocess({
 						cwd: this.session.cwd,
@@ -791,8 +746,7 @@ export class TaskTool implements AgentTool<TaskSchema, TaskToolDetails, Theme> {
 						settings: this.session.settings,
 						mcpManager: this.session.mcpManager,
 						contextFiles,
-						skills: task.resolvedSkills,
-						preloadedSkills: task.preloadedSkills,
+						skills: availableSkills,
 						promptTemplates,
 					});
 				}
@@ -842,8 +796,7 @@ export class TaskTool implements AgentTool<TaskSchema, TaskToolDetails, Theme> {
 						settings: this.session.settings,
 						mcpManager: this.session.mcpManager,
 						contextFiles,
-						skills: task.resolvedSkills,
-						preloadedSkills: task.preloadedSkills,
+						skills: availableSkills,
 						promptTemplates,
 					});
 					if (mergeMode === "branch" && result.exitCode === 0) {
@@ -927,7 +880,7 @@ export class TaskTool implements AgentTool<TaskSchema, TaskToolDetails, Theme> {

 			// Execute in parallel with concurrency limit
 			const { results: partialResults, aborted } = await mapWithConcurrencyLimit(
-				tasksWithSkills,
+				tasksWithContext,
 				maxConcurrency,
 				runTask,
 				signal,
@@ -938,7 +891,7 @@ export class TaskTool implements AgentTool<TaskSchema, TaskToolDetails, Theme> {
 				if (result !== undefined) {
 					return result;
 				}
-				const task = tasksWithSkills[index];
+				const task = tasksWithContext[index];
 				return {
 					index,
 					id: task.id,
@@ -7,7 +7,6 @@ interface RenderResult {
 	task: string;
 	id: string;
 	description: string;
-	skills?: string[];
 }

 /**
@@ -16,17 +15,16 @@ interface RenderResult {
 * If context is provided, it is prepended with a separator.
 */
 export function renderTemplate(context: string | undefined, task: TaskItem): RenderResult {
-	let { id, description, assignment, skills } = task;
+	let { id, description, assignment } = task;
 	assignment = assignment.trim();
 	context = context?.trim();

 	if (!context || !assignment) {
-		return { task: assignment || context!, id, description, skills };
+		return { task: assignment || context!, id, description };
 	}
 	return {
 		task: renderPromptTemplate(subagentUserPromptTemplate, { context, assignment }),
 		id,
 		description,
-		skills,
 	};
 }
@@ -44,11 +44,6 @@ export const taskItemSchema = Type.Object({
 		description:
 			"Complete per-task instructions the subagent executes. Must follow the Target/Change/Edge Cases/Acceptance structure. Only include per-task deltas — shared background belongs in `context`.",
 	}),
-	skills: Type.Optional(
-		Type.Array(Type.String(), {
-			description: "Skill names to preload into the subagent. Use only where it changes correctness.",
-		}),
-	),
 });
 export type TaskItem = Static<typeof taskItemSchema>;

@@ -41,7 +41,6 @@ const baseRenderContext: TemplateContext = {
 	planContent: "1. Read code\n2. Add tests",
 	planExists: true,
 	planFilePath: "local://PLAN.md",
-	preloadedSkills: [{ name: "semantic-compression", content: "preloaded skill content" }],
 	readFiles: ["packages/coding-agent/src/prompts/system/custom-system-prompt.md"],
 	repeatToolDescriptions: true,
 	reentry: false,
@@ -43,14 +43,4 @@ describe("renderTemplate", () => {
 		});
 		expect(result.task).toBe("just the assignment");
 	});
-
-	test("passes through skills", () => {
-		const result = renderTemplate(undefined, {
-			id: "X",
-			description: "label",
-			assignment: "do stuff",
-			skills: ["react", "postgres"],
-		});
-		expect(result.skills).toEqual(["react", "postgres"]);
-	});
 });