fix(task): stop using the spawn handle as the HUD description

The first HUD commit hid Name: Name. The cause was earlier: task
name was copied into identity.label, which became progress.description
and skipped generateTaskLabel. Keep the handle for id allocation, but
only treat eval label as a real UI description so the tiny-model
summary can run.

packages/coding-agent/CHANGELOG.md

@@ -24,6 +24,7 @@
 ### Fixed
 
 - Fixed the anchored Subagents HUD omitting the spawned agent role and repeating the spawn id as `Name: Name` when the generated label echoed the handle.
+- Stopped the task tool from using the spawn handle as the HUD description, which blocked tiny-model label generation and produced `Name: Name`.
 
 
 ## [17.3.5] - 2026-08-16

packages/coding-agent/src/modes/interactive-mode.ts

@@ -117,6 +117,7 @@ import { BUILTIN_SLASH_COMMAND_RESERVED_NAMES, buildTuiBuiltinSlashCommands } fr
 import { formatDuration } from "../slash-commands/helpers/format";
 import { STTController, type SttState } from "../stt";
 import { discoverTitleSystemPromptFile, resolvePromptInput } from "../system-prompt";
+import { labelEchoesHandle } from "../task/label";
 import { agentTypeBadge, formatTaskId } from "../task/render";
 import type { ConfiguredThinkingLevel } from "../thinking";
 import { tinyTitleClient } from "../tiny/title-client";
@@ -450,13 +451,6 @@ const MODEL_CYCLE_TRACK_CLEAR_MS = 4000;
 const SUBAGENT_HUD_VISIBLE_LIMIT = 8;
 const SUBAGENT_OBSERVER_UI_COALESCE_MS = 100;
 
-/** True when `label` is the spawn handle, including collision suffixes (`Name-2`). */
-function hudLabelEchoesId(id: string, label: string): boolean {
-	if (label.localeCompare(id, undefined, { sensitivity: "accent" }) === 0) return true;
-	const suffix = id.startsWith(`${label}-`) ? id.slice(label.length + 1) : "";
-	return /^\d+$/.test(suffix);
-}
-
 /**
  * Build the anchored subagent HUD block: a bold accent "Subagents" header plus
  * a bounded set of running-agent rows in the same `Id ⟨role⟩: description` shape
@@ -487,7 +481,7 @@ export function renderSubagentHudLines(sessions: ObservableSession[], columns: n
 				const badge = agentTypeBadge(role, theme);
 				let line = `${dot} ${theme.fg("accent", theme.bold(displayId))}${badge}`;
 				const description = session.description?.trim() || session.progress?.description?.trim();
-				const distinctDescription = description && !hudLabelEchoesId(session.id, description) ? description : undefined;
+				const distinctDescription = description && !labelEchoesHandle(session.id, description) ? description : undefined;
 				if (distinctDescription) {
 					const budget = Math.max(
 						TRUNCATE_LENGTHS.SHORT,
@@ -498,7 +492,7 @@ export function renderSubagentHudLines(sessions: ObservableSession[], columns: n
 					// No spawn description: fall back to a muted task preview, same as
 					// the inline task rows when a row has no label.
 					const taskPreview = session.progress?.task?.trim();
-					if (taskPreview && !hudLabelEchoesId(session.id, taskPreview)) {
+					if (taskPreview && !labelEchoesHandle(session.id, taskPreview)) {
 						line += ` ${theme.fg("muted", truncateToWidth(replaceTabs(taskPreview), TRUNCATE_LENGTHS.SHORT))}`;
 					}
 				}

packages/coding-agent/src/task/index.ts

@@ -1424,6 +1424,8 @@ export class TaskTool implements AgentTool<TaskToolSchemaInstance, TaskToolDetai
 				...(Object.hasOwn(params, "outputSchema") ? { outputSchema: params.outputSchema } : {}),
 				...(Object.hasOwn(params, "schemaMode") ? { schemaMode: params.schemaMode } : {}),
 				...(params.effort !== undefined ? { effort: params.effort } : {}),
+				// `name` is the spawn handle: keep it for id allocation when this
+				// path did not pre-reserve one. Do not treat it as a HUD description.
 				identity: { id: preAllocatedId, label: params.name },
 				index: spawnIndex,
 				parentToolCallId: toolCallId,

packages/coding-agent/src/task/label.ts

@@ -9,6 +9,14 @@ import { generateSessionTitle } from "../utils/title-generator";
 
 const TASK_LABEL_SYSTEM_PROMPT = prompt.render(taskLabelSystemPrompt);
 
+/** True when a generated label is just the spawn handle, including `Name-2`. */
+export function labelEchoesHandle(handle: string | undefined, label: string): boolean {
+	if (!handle) return false;
+	if (label.localeCompare(handle, undefined, { sensitivity: "accent" }) === 0) return true;
+	const suffix = handle.startsWith(`${label}-`) ? handle.slice(label.length + 1) : "";
+	return /^\d+$/.test(suffix);
+}
+
 /** Compresses a delegated assignment into a one-sentence UI label via the tiny title model — fired by the executor spawn path because the task wire schema no longer carries a `description`; null on empty input or failure. */
 export async function generateTaskLabel(
 	assignment: string,
@@ -20,7 +28,7 @@ export async function generateTaskLabel(
 	const text = assignment.trim();
 	if (!text) return null;
 	try {
-		return await generateSessionTitle(
+		const label = await generateSessionTitle(
 			text,
 			registry,
 			settings,
@@ -30,6 +38,8 @@ export async function generateTaskLabel(
 			TASK_LABEL_SYSTEM_PROMPT,
 			signal,
 		);
+		if (!label || labelEchoesHandle(sessionId, label)) return null;
+		return label;
 	} catch (err) {
 		logger.debug("task-label: generation failed", {
 			sessionId,

packages/coding-agent/src/task/structured-subagent.ts

@@ -393,7 +393,10 @@ function buildExecutorOptions(
 		assignment: request.assignment.trim(),
 		context: request.context?.trim() || undefined,
 		planReference: undefined,
-		description: trimToUndefined(request.identity?.label),
+		// Task `name` is the spawn handle (id allocation). Eval `label` is a
+		// real UI description. Copy it only for eval so generateTaskLabel can run.
+		description:
+			request.invocationKind === "eval" ? trimToUndefined(request.identity?.label) : undefined,
 		index: request.index ?? 0,
 		parentToolCallId: request.parentToolCallId,
 		detached: request.detached,
@@ -476,7 +479,8 @@ function buildFailureResult(
 			agentSource: policy.agent.source,
 			task: renderSubagentPrompt(request.assignment),
 			assignment: request.assignment.trim(),
-			description: trimToUndefined(request.identity?.label),
+			description:
+				request.invocationKind === "eval" ? trimToUndefined(request.identity?.label) : undefined,
 			exitCode: 1,
 			output: "",
 			stderr: message,

packages/coding-agent/test/task-label.test.ts

@@ -65,4 +65,34 @@ describe("task label generation", () => {
 		expect(requestSignal).toBe(controller.signal);
 		expect(await label).toBeNull();
 	});
+
+	it("rejects a generated label that only echoes the spawn handle", async () => {
+		const model = getModelOrThrow("claude-sonnet-4-5");
+		vi.spyOn(ai, "completeSimple").mockResolvedValue({
+			stopReason: "stop",
+			content: [{ type: "text", text: "<title>AuthLoader</title>" }],
+		} as never);
+
+		const echoed = await generateTaskLabel(
+			"Sleep forty seconds then reply done",
+			createRegistry(model),
+			createSettings(model),
+			"AuthLoader",
+		);
+		expect(echoed).toBeNull();
+
+		vi.spyOn(ai, "completeSimple").mockResolvedValue({
+			stopReason: "stop",
+			content: [{ type: "text", text: "<title>Sleep then reply done</title>" }],
+		} as never);
+		const labeled = await generateTaskLabel(
+			"Sleep forty seconds then reply done",
+			createRegistry(model),
+			createSettings(model),
+			"AuthLoader",
+		);
+		expect(labeled).toBe("Sleep then reply done");
+	});
+
+
 });

packages/coding-agent/test/task/structured-subagent.test.ts

@@ -186,6 +186,34 @@ describe("structured subagent primitive", () => {
 		expect(settled.result.modelRole).toBe("reviewer");
 		await fs.rm(settled.artifactsDir, { recursive: true, force: true });
 	});
+	it("does not treat a spawn handle as the HUD description", async () => {
+		mockDiscovery();
+		const dispatched: executorModule.ExecutorOptions[] = [];
+		vi.spyOn(executorModule, "runSubprocess").mockImplementation(async options => {
+			dispatched.push(options);
+			return result();
+		});
+
+		const handleOnly = await runStructuredSubagent(
+			request({ identity: { id: "AuthLoader", label: "AuthLoader" }, retainArtifacts: true }),
+		);
+		expect(dispatched[0]?.description).toBeUndefined();
+		expect(dispatched[0]?.id).toBe("AuthLoader");
+		await fs.rm(handleOnly.artifactsDir, { recursive: true, force: true });
+
+		dispatched.length = 0;
+		const evalLabeled = await runStructuredSubagent(
+			request({
+				invocationKind: "eval",
+				identity: { label: "Refactor the auth flow" },
+				retainArtifacts: true,
+			}),
+		);
+		expect(dispatched[0]?.description).toBe("Refactor the auth flow");
+		await fs.rm(evalLabeled.artifactsDir, { recursive: true, force: true });
+	});
+
+
 	it("derives modelRole from the raw selector source in request, override, definition order", async () => {
 		const customAgent = { ...AGENT, model: ["@definition"] };
 		mockDiscovery(customAgent);