the model tends to often randomly try to "simplify" existing logic...breaking existing functionality in the process.
Even elaborate AGENTS.md rules do only help a little bit.
(do not touch code unrelated to the task, do not simplify, minimise, "cut down" any existing logic without beeing explicitly and specifically asked to)
codex is pretty unusable if it does this and I'll have to read the whole protocols just to check if it decided to "simplify" something again