diff --git a/.agents/skills/review-docs-pr/SKILL.md b/.agents/skills/review-docs-pr/SKILL.md
index 2c37a8f7..74967cfb 100644
--- a/.agents/skills/review-docs-pr/SKILL.md
+++ b/.agents/skills/review-docs-pr/SKILL.md
@@ -234,7 +234,7 @@ short-lived token after the cloud agent returns.
            f"## Review summary\n{review['summary'].strip()}\n\n"
            f"## Findings\n{findings_text}\n\n"
            f"## Verdict\n{os.environ['VERDICT']}\n\n"
-           f"## Review signal\n[SIGNAL:pr-review] {json.dumps(signal, sort_keys=True)}"
+           f"<!-- [SIGNAL:pr-review] {json.dumps(signal, sort_keys=True)} -->"
        ),
        "comments": review["comments"],
    }
diff --git a/.agents/skills/review-docs-pr/test_publishing_snippet.py b/.agents/skills/review-docs-pr/test_publishing_snippet.py
new file mode 100644
index 00000000..48e32a5d
--- /dev/null
+++ b/.agents/skills/review-docs-pr/test_publishing_snippet.py
@@ -0,0 +1,132 @@
+#!/usr/bin/env python3
+"""Regression test for the manual review-publishing snippet in SKILL.md.
+
+`review-docs-pr/SKILL.md` documents two ways a `[SIGNAL:pr-review]` record
+reaches GitHub: the automated `agent-docs-review.yml` workflow, which calls
+`doc_quality_policy/publish_review_signal.py`, and the manual/interactive
+path documented under "Publishing a GitHub review" here, whose python
+snippet independently builds the same review body. The two must stay in
+sync: PR #686 hid the signal behind an HTML comment in
+`publish_review_signal.py` but initially left this documented snippet
+rendering it under a visible "## Review signal" heading, so a manually
+published review kept leaking the machine-readable record into GitHub's
+rendered PR body.
+
+This extracts the documented bash+python snippet and runs it against a
+stubbed `review.json` and signal file, exercising the exact text agents
+copy rather than a paraphrase of it.
+
+Run with: python3 .agents/skills/review-docs-pr/test_publishing_snippet.py
+"""
+from __future__ import annotations
+
+import importlib.util
+import json
+import re
+import subprocess
+import sys
+import tempfile
+import unittest
+from pathlib import Path
+
+HERE = Path(__file__).resolve().parent
+SKILL = HERE / "SKILL.md"
+
+_spec = importlib.util.spec_from_file_location(
+    "verify_review_signal",
+    HERE.parent / "doc_quality_policy" / "verify_review_signal.py",
+)
+vrs = importlib.util.module_from_spec(_spec)
+sys.modules[_spec.name] = vrs
+_spec.loader.exec_module(vrs)
+
+
+def extract_publishing_snippet(signal_path: Path, request_path: Path) -> str:
+    """Extract the documented python heredoc that builds the pinned review payload.
+
+    Retargets the hardcoded `/tmp/review-signal.json` and
+    `/tmp/review-request.json` paths to test-local paths so the test does
+    not read or write real `/tmp` state.
+    """
+    text = SKILL.read_text(encoding="utf-8")
+    anchor = text.index("2. Write the signal JSON object")
+    match = re.search(r"```bash\n((?: {3}[^\n]*\n|\n)+?) {3}```", text[anchor:])
+    if not match:
+        raise AssertionError("publishing snippet not found in review-docs-pr/SKILL.md")
+    lines = match.group(1).splitlines()
+    dedented = "\n".join(line[3:] if line.startswith("   ") else line for line in lines)
+    dedented = dedented.replace("/tmp/review-signal.json", str(signal_path))
+    dedented = dedented.replace("/tmp/review-request.json", str(request_path))
+    return dedented
+
+
+class PublishingSnippetTest(unittest.TestCase):
+    def _run(self, *, comments=None, summary="Looks good.", verdict="Approve"):
+        with tempfile.TemporaryDirectory() as tmp:
+            root = Path(tmp)
+            signal_path = root / "review-signal.json"
+            request_path = root / "review-request.json"
+            (root / "review.json").write_text(
+                json.dumps({"summary": summary, "comments": comments or []}),
+                encoding="utf-8",
+            )
+            signal = {
+                "pr": "1",
+                "head_sha": "sha1",
+                "verdict": verdict,
+                "critical": 0,
+                "important": 0,
+                "reviewer_login": "some-reviewer",
+            }
+            signal_path.write_text(json.dumps(signal), encoding="utf-8")
+
+            snippet = extract_publishing_snippet(signal_path, request_path)
+            snippet = snippet.replace(
+                'HEAD_SHA="<evaluated PR head SHA>"', 'HEAD_SHA="sha1"'
+            )
+            snippet = snippet.replace(
+                'VERDICT="<Approve|Approve with nits|Request changes>"',
+                f'VERDICT="{verdict}"',
+            )
+
+            result = subprocess.run(
+                ["bash", "-c", snippet],
+                cwd=root,
+                capture_output=True,
+                text=True,
+                stdin=subprocess.DEVNULL,
+                timeout=10,
+            )
+            self.assertEqual(result.returncode, 0, result.stderr)
+            payload = json.loads(request_path.read_text(encoding="utf-8"))
+        return payload, signal
+
+    def test_signal_is_hidden_in_html_comment(self):
+        payload, _ = self._run()
+        self.assertNotIn("## Review signal", payload["body"])
+        self.assertIn("<!-- [SIGNAL:pr-review]", payload["body"])
+
+    def test_hidden_signal_remains_parseable(self):
+        payload, signal = self._run()
+        parsed, problems = vrs._parse_signal(
+            payload["body"], signal["pr"], signal["head_sha"]
+        )
+        self.assertEqual(problems, [])
+        self.assertEqual(parsed["verdict"], signal["verdict"])
+
+    def test_findings_and_verdict_are_still_rendered(self):
+        payload, _ = self._run(
+            comments=[{"path": "a.md", "line": 3, "body": "Fix this typo."}],
+            verdict="Request changes",
+        )
+        self.assertIn("## Findings", payload["body"])
+        self.assertIn("`a.md:3` — Fix this typo.", payload["body"])
+        self.assertIn("## Verdict\nRequest changes", payload["body"])
+        self.assertEqual(payload["event"], "REQUEST_CHANGES")
+
+
+if __name__ == "__main__":
+    if sys.platform.startswith("win"):
+        print("skipping: publishing snippet requires bash")
+        sys.exit(0)
+    unittest.main()
diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 2a818ef5..d4857af5 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -65,6 +65,13 @@ jobs:
           python3 .agents/skills/doc_quality_policy/test_publish_review_signal.py
           python3 .agents/skills/doc_quality_policy/test_manifest.py
 
+      # Extracts the documented manual review-publishing snippet from
+      # review-docs-pr/SKILL.md and runs it against a stub, so CI catches
+      # this documented path drifting from publish_review_signal.py (e.g.
+      # the signal-hiding format going out of sync between the two).
+      - name: Test review-docs-pr publishing snippet
+        run: python3 .agents/skills/review-docs-pr/test_publishing_snippet.py
+
       - name: Test validate_ui_refs --changed mode and snapshot provenance
         run: python3 .agents/skills/validate_ui_refs/test_changed_mode.py