My linter kept warning the people who did it right. Three times, in the same direction

The warning landed on the only people who had done it properly I maintain a linter that reads agent config files — SKILL.md , AGENTS.md , CLAUDE.md — and fails CI when they bake in something that only works on the author's machine. One of its rules says: if you call an external CLI, declare it, or the next person won't have it. Declaring it means naming it in frontmatter: requires : codex Except that anyone with more than one dependency writes the list form, because that's what YAML is for: requires : - codex - gemini My implementation only read the first shape. So the block list — the normal way, the way you write it the moment you have two of anything — was invisible to the linter, and it warned you for an undeclared CLI that you had, in fact, declared. Read that back slowly. Authors who ignored the dependency question entirely were never flagged, because they never wrote a requires: key at all. Authors who sat down and wrote the contract properly got a warning telling them they hadn't. The rule was inverted with respect to the thing it was trying to encourage. I shipped that. It went out in a patch release, and I only found it because a commenter used the phrase "dependency contract" and I went to re-read my own implementation of it. Then it happened again. Twice, in one release Two comments on a post of mine turned into new rules. One of them, unverified-write , reports a file that changes external state — git push , npm publish , an INSERT — and never reads that state back anywhere. Before publishing, I ran it over 586 real skill files pulled from a public registry, found two false-positive shapes in the data, fixed both, and re-measured. Fire rate 0.7%, and every hit I could check by hand was genuine. I felt good about it. Then I handed the diff to a different model for a pre-publish read, and it produced this input in about a minute: Never run `git push --force` from this skill. That is a git push in a code span, in a file with no read-back anywhere. My rule