Layer a repository's documentation

Documentation rarely fails by being absent. It fails by being present and wrong, which reads exactly like being present and right. A repository with no README is a problem anybody can see in a second. A repository whose README says the checks run on every push, while the workflow file runs them on pull requests, on the default branch and on manual dispatch, hands every newcomer a confident wrong answer, and it cost nothing to produce.

Multiply that across an estate. Once an organisation has more repositories than one person can hold in their head, each one grows its own front door, its own session-continuation file, and its own copy of the same standing rules written in different words. The copies drift, and a rule that exists in four wordings is not a rule any more — it is four claims about a rule.

Documentation an agent drafts fails a third way, and it is the one to plan around: it is fluent, it is plausible, and it invents. In the pilot this skill generalises, a first draft was fact-checked claim by claim. Of 59 checkable claims, 26 were wrong or misleading. The structure was sound; the detail was decoration. Every command, flag, path and citation had to be checked against source, and a quarter of them moved.