Exempt task tool from the generic tool-execution watchdog

The task tool runs an entire sub-agent that carries its own bounds
(maxTurns, no-progress, thrash, opt-in deadlineMs). The uniform per-tool
wall-clock budget (default 660s) aborted healthy workers past 11 minutes
through the cancel path. resolveToolExecutionTimeoutMs now returns
undefined for task calls, and the opt-in sub-agent deadline is no longer
clamped under an outer watchdog that no longer applies.

Author: TheGreatAxios

docs/ARCHITECTURE.md

@@ -376,7 +376,7 @@ tool call
 - **queue** — Headless settle registry (`src/permission/queue.ts`). Surfaces enqueue outstanding requests; `wirePermissionGrantReconciliation` listens for `permission.grant` and drains every queued request the new grant covers, without a second prompt. Teardown calls `drain()` so no awaited resolve is left hanging.
 - **types** — `Approval`, `ApprovalScope`, `PermissionRequest`, `ApprovalOutcome`.
 
-**Tool wall-clock budget vs. permission prompts.** Each tool `run()` is wrapped by an outer execution watchdog (`src/tui/tool-execution-watchdog.ts`, defaults ~11 min). By default (`tools.waitForApproval`, Settings → Tools, **On**), that budget freezes while the operator is deciding on a permission prompt, so a late approve still runs the tool and the agent waits for the decision instead of timing out under the modal. When **Off**, the budget keeps ticking during the prompt; if it expires first the tool is skipped and the permission modal is dismissed via the budget AbortSignal (auto-deny with a timeout message). The TUI permission queue (`src/tui/gate-wire.ts`, backed by `src/permission/queue.ts`) attaches that signal so ghost prompts cannot outlive an already-aborted tool.
+**Tool wall-clock budget vs. permission prompts.** Each tool `run()` is wrapped by an outer execution watchdog (`src/tui/tool-execution-watchdog.ts`, defaults ~11 min). The `task` tool is exempt — a sub-agent run is bounded by its own limits (maxTurns, no-progress, thrash, opt-in deadline), so the generic per-tool budget never aborts a healthy long-running worker. By default (`tools.waitForApproval`, Settings → Tools, **On**), that budget freezes while the operator is deciding on a permission prompt, so a late approve still runs the tool and the agent waits for the decision instead of timing out under the modal. When **Off**, the budget keeps ticking during the prompt; if it expires first the tool is skipped and the permission modal is dismissed via the budget AbortSignal (auto-deny with a timeout message). The TUI permission queue (`src/tui/gate-wire.ts`, backed by `src/permission/queue.ts`) attaches that signal so ghost prompts cannot outlive an already-aborted tool.
 
 Approval scopes offered: Allow Once (persist nothing), Allow Always for a file or its directory (file tools), or a command shape (shell). There is intentionally no "all files" rung. Project-scoped Allow Always grants are confined to the session that minted them: they match the session root and its registered git worktrees (`cwdMatchesGrant` in `src/permission/authz-grants.ts` via `createWorktreeRootsProvider`), not bare process-cwd equality — so a grant at the repo root still covers a sub-agent running in a sibling worktree of the same project.
 

docs/IMPLEMENTATION.md

@@ -230,7 +230,7 @@ Provider and model configuration lives in JSON settings files. The global file h
   }
   ```
 
-  - `timeoutMs` / `maxTimeoutMs` — outer execution watchdog around each tool `run()` (defaults ~11 min / 30 min).
+  - `timeoutMs` / `maxTimeoutMs` — outer execution watchdog around each tool `run()` (defaults ~11 min / 30 min). The `task` tool is exempt: a dispatched sub-agent is bounded by its own limits (maxTurns, no-progress, thrash, opt-in `deadlineMs`), not the generic per-tool budget.
   - `waitForApproval` (default **true** when unset) — freeze that budget while a permission prompt is open so a late approve still runs the tool. **Settings → Tools** toggles this live for the next tool call and persists it here. When **false**, the budget keeps ticking during the prompt; on expiry the tool is skipped and the modal is auto-dismissed. The freeze is bounded: after **30 minutes** with the prompt still unanswered the budget resumes ticking on its own, so a prompt that never becomes visible (overlay open, UI gone) cannot hang a tool run indefinitely.
 
   Optional `subagentMaxTurns` (integer **1–100**, default **30**) sets the default inference-turn budget for dispatched workers (not the parent chat session limit). Per-dispatch `task(maxTurns)` and agent profile `maxTurns` override this default; values above **100** are rejected on `task` and clamped for profiles. Always applies — the primary session is always orchestrator-capable (CL-5814).

src/subagent/run.ts

@@ -61,7 +61,6 @@ import {
   resolveDefaultSubAgentMaxTurns,
   toolWatchdogFromSettings,
 } from "../config/settings.js";
-import { resolveToolExecutionTimeoutMs } from "../tui/tool-execution-watchdog.js";
 import { createSearchAgentsTool } from "../agent/agent-search.js";
 import { manageTasksDefinition, parseManageTasksArgs } from "../agent/tasks.js";
 import { ID_PREFIX } from "../branding.js";
@@ -284,16 +283,14 @@ export async function runSubAgent(params: RunSubAgentParams): Promise<string> {
   // visible to the finally block, which is a sibling scope, not a child.
   let stallWatchdog: ReturnType<typeof setInterval> | undefined;
   // Combines the caller's cancel signal with an optional opt-in wall-clock
-  // deadline so a leaf that hits the deadline can still return a salvage report
-  // rather than racing the outer per-tool-call watchdog (which would discard the
-  // run wholesale). When deadlineMs is omitted, no timer is armed — maxTurns +
-  // cancel remain the only bounds. Declared before try so finally can dispose.
+  // deadline so a leaf that hits the deadline can still return a salvage
+  // report. When deadlineMs is omitted, no timer is armed — maxTurns + cancel
+  // remain the only bounds. Declared before try so finally can dispose.
+  // The task tool is exempt from the generic per-tool watchdog (see
+  // resolveToolExecutionTimeoutMs), so there is no outer budget to clamp under.
   const resolvedDeadlineMs =
     params.deadlineMs !== undefined
-      ? resolveSubAgentDeadlineMs(
-          params.deadlineMs,
-          resolveToolExecutionTimeoutMs(toolWatchdogFromSettings(params.settings)),
-        )
+      ? resolveSubAgentDeadlineMs(params.deadlineMs, undefined)
       : undefined;
   const runController = createSubAgentRunController(params.signal, resolvedDeadlineMs);
 

src/subagent/task-tool.ts

@@ -178,8 +178,9 @@ export type TaskToolDeps = SubAgentSandboxDeps & {
   spawnAllowlist?: readonly string[];
   /**
    * Optional wall-clock budget (ms) for each worker this tool spawns. Opt-in
-   * only — there is no default leaf death clock. When set, clamped below the
-   * outer tool-execution watchdog so a salvage report can return first.
+   * only — there is no default leaf death clock. The task tool is exempt from
+   * the generic tool-execution watchdog, so this deadline is the only
+   * wall-clock bound on a worker.
    */
   deadlineMs?: number;
 

src/tui/tool-execution-watchdog.test.ts

@@ -39,6 +39,35 @@ describe("tool execution watchdog", () => {
     ).toBeUndefined();
   });
 
+  test("task is exempt from the settings watchdog", () => {
+    // Sub-agents carry their own bounds (maxTurns, no-progress, thrash,
+    // opt-in deadline); the generic per-tool budget must not abort them.
+    const call = { id: "1", name: "task", arguments: {} };
+    expect(resolveToolExecutionTimeoutMs({ defaultMs: 660_000 }, call)).toBeUndefined();
+    expect(
+      resolveToolExecutionTimeoutMs({ defaultMs: 660_000, maxMs: 1_800_000 }, call),
+    ).toBeUndefined();
+  });
+
+  test("task run outlasting the generic budget completes with its own report", async () => {
+    const runner = createDynamicToolRunner(
+      [
+        stringTool("task", async () => {
+          // Slow but progressing: runs well past the 30ms generic budget.
+          await new Promise((r) => setTimeout(r, 120));
+          return "## Summary\nworker report";
+        }),
+      ],
+      { defaultMs: 30 },
+    );
+    const result = await runner.run(
+      { id: "t", name: "task", arguments: {} },
+      new AbortController().signal,
+    );
+    expect(result.isError).toBeUndefined();
+    expect(result.content).toContain("worker report");
+  });
+
   test("omitted config does not arm a default watchdog", () => {
     expect(resolveToolExecutionTimeoutMs(undefined)).toBeUndefined();
     expect(resolveToolExecutionTimeoutMs({})).toBeUndefined();

src/tui/tool-execution-watchdog.ts

@@ -50,11 +50,16 @@ const BUDGET_EXPIRED = Symbol("tool-execution-budget-expired");
  * run_shell passes a positive arguments.timeout (requested + slack so this
  * layer cannot beat shell-guard). A requested run_shell timeout is not clamped
  * to MAX_TOOL_EXECUTION_TIMEOUT_MS or tools.maxTimeoutMs.
+ *
+ * The task tool is exempt: it runs an entire sub-agent that carries its own
+ * bounds (maxTurns, no-progress, thrash, opt-in deadline), so the generic
+ * per-tool budget would abort healthy long-running workers mid-run.
  */
 export function resolveToolExecutionTimeoutMs(
   config?: ToolWatchdogConfig,
   call?: ToolCall,
 ): number | undefined {
+  if (call?.name === "task") return undefined;
   if (call?.name === "run_shell") {
     const requested = requestedRunShellTimeoutMs(call);
     if (requested !== undefined) {