I resent everything about this.
But I write the .md files because others on the team are not as good at Just Talking To It. The md files are there because juniors don't know what to ask for.
(Or the equivalent incantations for other languages)
They aren't there for others, they are there to make sure the code produced measures up to my standards. Sure, it helps that it also applies to requests made by others, but that's a bonus.
My point is the all knowing all seeing big brain super bot should already know how to write good code. It feels dumb that we have to keep reminding it
I caught it ignoring the prompt’s details, so added “include the output of the Unix ‘date’ command with each response.
And that worked great in that its absence became an indicator that Claude was off-prompt. Until it started including made-up strings that resembled, but had nothing to do with, the output of the Unix ‘date’ command.
Given your description of the behavior, my guess is context window compression bit you. Less likely if it's a root level CLAUDE.md and you used a recent version of Claude Code.
AGENTS.md is a poor substitute for agents actually learning, but it somewhat works.
And sure, you can (and should) enforce constraints via githooks whenever you can (determinism is good), but if the agent only finds out at checkin time, it's created a whole bunch of code it needs to redo, and that doesn't run properly if you do the caveman thing and actually run your code before committing. Again, token & context waste.