1 changed files with 10 additions and 0 deletions
@@ -65,6 +65,16 @@ Each of these produced a wrong conclusion before it was written down.
    conclusion drawn from it describes the wrong tree. Confirm `git rev-parse --show-toplevel`
    is the tree you think it is before trusting any git output.

+13. **Run the repository's PINNED tool version, not `npx --yes <tool>`.** `npx --yes` ignores the
+    lockfile and fetches the latest release, so it answers about a version the project does not
+    use. Measured on mosaicstack#1313: the lockfile pins prettier 3.8.1, under which three guides
+    pass; `npx --yes prettier` fetched 3.9.6, under which the same three fail; and 3.0.0, the floor
+    of the declared `^3.0.0` range, fails a different one. Three versions, three verdicts, same
+    bytes. Use `node_modules/.bin/<tool>`, or name the version the lockfile pins.
+14. **A formatter or linter declared as a range is a dated verdict, not a fact.** If a lockfile
+    pins it, the gate is reproducible today and will disagree with itself the day the pin moves.
+    Report a formatting failure with the version that produced it, always.
+
 ### Feedback Categories

 - **Blocker**: must fix before merge (security, bugs, test failures)