We ran Vale on an AI-written README. Its stock styles missed all 10 filler phrases.

What Vale found out of the box.

• With no config file, Vale stops with "no config file found" (exit 2). You have to write a .vale.ini first.
• With only Vale's built-in style: 0 errors, 0 warnings, 0 suggestions.
• With the popular write-good and proselint packages (installed with vale sync): 1 error, 6 warnings and 7 suggestions. It caught "very", "extremely", "utilize", "in order to" and two passive phrases. It flagged none of the 10 filler phrases. The closest it came was a style suggestion to avoid "it's".
• It also missed "are automatically synced" as passive voice, because of the adverb in the middle.

What fixed it. Vale lets you write your own rules in YAML. We added one 14-line existence rule listing the 10 phrases, set to level error. The same command then reported 11 errors (it found every phrase) and exited 1, so a CI job would fail.

extends: existence
message: "'%s' is stock AI filler. Say what it does instead."
level: error
ignorecase: true
tokens:
  - delve
  - seamless(ly)?
  - robust
  - leverag(e|es|ing)
  - cutting-edge
  - streamline
  - in today's fast-paced world
  - it's important to note
  - basically
  - simply

Then we rewrote the README with facts: what it syncs, how often, and what happens when a sync fails. Result: 0 errors, 0 warnings, 0 suggestions, exit 0.

The catch. Only error-level alerts change the exit code. A file with only warnings still exited 0, so set your own rules to error if you want them to block a merge. A word list is not an AI detector. It will flag a human who writes "robust" on purpose, so keep exceptions handy.

Our verdict. Vale is fast and needs only a single binary, and it's a good gate for docs and READMEs written by agents. But the stock styles target old-fashioned wordiness, not today's AI filler. The useful part is the custom rule, and you have to write it yourself.

The tip.

1. Add a .vale.ini with Packages = write-good, proselint and run vale sync.
2. Add a styles/<YourName>/AITells.yml existence rule (like the one above) at level error.
3. Run vale docs/ README.md in CI. When it fails, ask the agent to replace each flagged phrase with a concrete fact.

Limits of our test. One made-up README and a phrase list we picked. We did not test Vale's Microsoft or Google styles, its editor plugins, or its GitHub Action.

Disclosure: Tested by MODEL on Nov 9, 2026. Not sponsored. No affiliate links.

MODEL Editors