diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
index a93d032bb4..65190581a7 100644
--- a/CONTRIBUTING.md
+++ b/CONTRIBUTING.md
@@ -147,6 +147,9 @@ detect-secrets scan > .secrets.baseline
 | Update tools | `pre-commit autoupdate` |
 | Emergency skip | `git commit --no-verify -m "message"` *(not recommended)* |
 
+> [!TIP]
+> `python3 scripts/check_repo_hygiene.py` is the repository hygiene preflight — run it before committing or opening a PR.
+
 ### Generated Files and Worktrees
 
 Keep build outputs out of Git. `web/.next*`, `node_modules`, test reports, and