diff --git a/test/review.test.js b/test/review.test.js
index 1364502..bcbe3b8 100644
--- a/test/review.test.js
+++ b/test/review.test.js
@@ -44,6 +44,25 @@ test('agentFailureDetail 在 debug 模式輸出遮罩後片段', () => {
   }
 });
 
+test('agentFailureDetail 先限長再遮罩並處理常見 PII', () => {
+  const oldDebug = process.env.ACTIONS_STEP_DEBUG;
+  process.env.ACTIONS_STEP_DEBUG = 'true';
+  try {
+    const detail = diagnostics.agentFailureDetail({
+      ok: false,
+      error: Object.assign(new Error('boom'), { code: 3 }),
+      stderr: `${'x'.repeat(520)} token=should-not-be-scanned`,
+      output: 'user@example.test eyJaaaaaaaaaa.bbbbbbbbbb.cccccccccc',
+    });
+    assert.match(detail, /exit 3/);
+    assert.doesNotMatch(detail, /should-not-be-scanned|user@example.test|eyJaaaaaaaaaa/);
+    assert.match(detail, /stdout：\*\*\* \*\*\*/);
+  } finally {
+    if (oldDebug === undefined) delete process.env.ACTIONS_STEP_DEBUG;
+    else process.env.ACTIONS_STEP_DEBUG = oldDebug;
+  }
+});
+
 test('postOthersToIssue 依序送出 issue 留言以維持排序', async () => {
   const calls = [];
   let active = 0;