diff --git a/tools/lint_gate.py b/tools/lint_gate.py
index e1109b4..c40c8c4 100644
--- a/tools/lint_gate.py
+++ b/tools/lint_gate.py
@@ -122,15 +122,60 @@ def describe(finding: dict) -> str:
     )
 
 
+def run_doc_gate(force_all: bool) -> dict:
+    """Run the workspace documentation gate and return its JSON payload.
+
+    Delegates to the single authoritative script in the workspace root. Deliberately not a
+    fourth copy of any lint logic in this repo: this file is already duplicated across three
+    repositories and has drifted, so the doc rules live in exactly one place.
+    """
+    script = REPO.parent / "scripts" / "doc_lint.py"
+    if not script.is_file():
+        return {"status": "unavailable", "findings": [], "baselined": []}
+    cmd = [sys.executable, str(script), "--json"]
+    if force_all:
+        cmd.append("--all")
+    result = subprocess.run(cmd, capture_output=True, text=True, encoding="utf-8", check=False)
+    if not result.stdout.strip():
+        print(f"lint_gate: doc gate produced no output: {result.stderr.strip()[:200]}", file=sys.stderr)
+        return {"status": "error", "findings": [], "baselined": []}
+    try:
+        return json.loads(result.stdout)
+    except json.JSONDecodeError:
+        print("lint_gate: could not parse doc gate output", file=sys.stderr)
+        return {"status": "error", "findings": [], "baselined": []}
+
+
 def main(argv: list[str] | None = None) -> int:
     parser = argparse.ArgumentParser(description=__doc__.splitlines()[0])
     parser.add_argument("--base", default=None, help="compare against this ref (e.g. origin/main)")
     parser.add_argument("--files", nargs="*", default=None, help="explicit files to check")
     parser.add_argument("--all", action="store_true", help="run the gate rules over the whole repo")
     parser.add_argument("--json", action="store_true", help="machine-readable result on stdout")
+    parser.add_argument("--no-docs", action="store_true",
+                        help="skip the workspace documentation gate")
     args = parser.parse_args(argv)
 
-    ruff = find_ruff()
+    # Documentation: changed Markdown by default, the whole corpus under --all. `--files` names
+    # Python files explicitly, so it disables the doc gate rather than misreading them as docs.
+    docs: dict = {"status": "skipped", "findings": [], "baselined": []}
+    if not args.no_docs and args.files is None:
+        docs = run_doc_gate(force_all=args.all)
+
+    # Report the documentation verdict even when Ruff is unavailable: a missing linter must not
+    # hide the docs result, and the exit code still signals the environment problem.
+    try:
+        ruff = find_ruff()
+    except SystemExit as exc:
+        doc_findings = docs.get("findings") or []
+        if doc_findings:
+            print(f"docs: {len(doc_findings)} finding(s) (see docs/AUTHORING.md):", file=sys.stderr)
+            for finding in doc_findings:
+                print(f"  {finding['file']}: {finding['check']}: {finding['message']}",
+                      file=sys.stderr)
+        else:
+            print(f"docs: clean ({docs.get('status')})", file=sys.stderr)
+        return int(exc.code or 2)
 
     if args.all:
         targets = [str(REPO)]
@@ -139,8 +184,9 @@ def main(argv: list[str] | None = None) -> int:
         if not targets:
             print("lint_gate: no changed Python files; nothing to check.")
             if args.json:
-                print(json.dumps({"findings": [], "checked": [], "status": "clean"}))
-            return 0
+                print(json.dumps({"findings": [], "checked": [], "docs": docs,
+                                  "status": "findings" if docs.get("findings") else "clean"}))
+            return 1 if docs.get("findings") else 0
 
     findings, version = run_ruff(ruff, ["--select", GATE_SELECT, *targets])
     report_only, _ = run_ruff(ruff, ["--select", REPORT_ONLY, *targets])
@@ -164,12 +210,13 @@ def main(argv: list[str] | None = None) -> int:
                         for f in findings
                     ],
                     "unused_suppressions": [describe(f) for f in report_only],
-                    "status": "findings" if findings else "clean",
+                    "docs": docs,
+                    "status": "findings" if (findings or docs.get("findings")) else "clean",
                 },
                 indent=2,
             )
         )
-        return 1 if findings else 0
+        return 1 if (findings or docs.get("findings")) else 0
 
     print(f"lint_gate: {version}")
     print(f"  select   {GATE_SELECT}  (BLE001 is allowed by policy; see ruff.toml)")
@@ -185,8 +232,19 @@ def main(argv: list[str] | None = None) -> int:
         print(f"\n{len(report_only)} unused suppression(s) to triage by hand (never auto-removed):")
         for finding in report_only:
             print(f"  {describe(finding)}")
-    print(f"\nstatus: {'FINDINGS' if findings else 'clean'}")
-    return 1 if findings else 0
+
+    doc_findings = docs.get("findings") or []
+    if docs.get("status") == "unavailable":
+        print("\ndocs: workspace doc gate not found; skipped")
+    elif doc_findings:
+        print(f"\ndocs: {len(doc_findings)} finding(s) (see docs/AUTHORING.md):")
+        for finding in doc_findings:
+            print(f"  {finding['file']}: {finding['check']}: {finding['message']}")
+    else:
+        print(f"\ndocs: clean ({docs.get('status')})")
+
+    print(f"\nstatus: {'FINDINGS' if (findings or doc_findings) else 'clean'}")
+    return 1 if (findings or doc_findings) else 0
 
 
 if __name__ == "__main__":