diff --git a/packages/cli/src/hooks/maxsim-task-completed.ts b/packages/cli/src/hooks/maxsim-task-completed.ts
index 0e0a9414..26a57dd4 100644
--- a/packages/cli/src/hooks/maxsim-task-completed.ts
+++ b/packages/cli/src/hooks/maxsim-task-completed.ts
@@ -10,6 +10,16 @@
  *  - Always handles errors gracefully — never crashes.
  */
 
+/**
+ * Output formats:
+ * - Exit 0: Allow task completion (all gates passed)
+ * - Exit 2 + stderr: Block completion — gates failed, agent must fix before completing
+ * - JSON stdout { continue: false, stopReason: "..." } + exit 0: Stop the teammate entirely
+ *
+ * Currently uses exit 2 (block + report) when test/build/lint gates fail.
+ * Use stopTeammate() from shared.ts for permanent stop scenarios.
+ */
+
 import * as fs from 'node:fs';
 import * as path from 'node:path';
 import { spawnSync } from 'node:child_process';
diff --git a/packages/cli/src/hooks/maxsim-teammate-idle.ts b/packages/cli/src/hooks/maxsim-teammate-idle.ts
index 96aa0ecd..ef85b17d 100644
--- a/packages/cli/src/hooks/maxsim-teammate-idle.ts
+++ b/packages/cli/src/hooks/maxsim-teammate-idle.ts
@@ -9,6 +9,16 @@
  *  - Always handles errors gracefully — never crashes.
  */
 
+/**
+ * Output formats:
+ * - Exit 0: Allow the teammate to remain idle (no pending tasks)
+ * - Exit 2 + stderr: Block idle and redirect — "Pick up the next available task."
+ * - JSON stdout { continue: false, stopReason: "..." } + exit 0: Stop the teammate entirely
+ *
+ * Currently uses exit 2 (block + redirect) when pending tasks exist.
+ * Use stopTeammate() from shared.ts for permanent stop scenarios.
+ */
+
 import * as fs from 'node:fs';
 import * as os from 'node:os';
 import * as path from 'node:path';
diff --git a/packages/cli/src/hooks/shared.ts b/packages/cli/src/hooks/shared.ts
index 99d86136..8e2c19bd 100644
--- a/packages/cli/src/hooks/shared.ts
+++ b/packages/cli/src/hooks/shared.ts
@@ -103,13 +103,15 @@ export function playSound(soundFile: string): void {
       // For named system sounds (no extension) fall back to rundll32.
       const isWav = soundFile.toLowerCase().endsWith('.wav');
       if (isWav) {
+        // Use double-quoted string which handles spaces and most special chars
+        const escaped = soundFile.replace(/"/g, '\\"');
         spawnSync(
           'powershell',
           [
             '-NoProfile',
             '-NonInteractive',
             '-Command',
-            `$p='${soundFile.replace(/'/g, "''")}'; (New-Object System.Media.SoundPlayer $p).PlaySync()`,
+            `$p="${escaped}"; (New-Object System.Media.SoundPlayer $p).PlaySync()`,
           ],
           { stdio: 'ignore' },
         );
@@ -135,3 +137,17 @@ export function playSound(soundFile: string): void {
     // Never crash on sound failure
   }
 }
+
+/**
+ * Send a JSON stop signal to terminate a teammate.
+ * Outputs the stop payload to stdout and exits cleanly.
+ * Use this when a teammate should be permanently stopped (not just blocked).
+ *
+ * For blocking (retry behavior), use: process.stderr.write(msg); process.exit(2);
+ * For stopping (permanent), use: stopTeammate(reason);
+ */
+export function stopTeammate(reason: string): never {
+  const payload = JSON.stringify({ continue: false, stopReason: reason });
+  process.stdout.write(`${payload}\n`);
+  process.exit(0);
+}