I had Claude Code losing its mind because of something outside of its control, one of the formatters used by Zed for Python kept messing with HTML templates, which are insanely sensitive to line breaks in some template specific code statements. Zed kept adding line breaks without reason other than some tool just did it. Claude kept trying to fix it, going to the extreme of using ed to force it, I watched it lose its mind till I asked "I think Zed is formatting the file every time you save?" turns out, yes, yes it was. It wasn't an issue when it used ed, but when Claude or I would change the file again, it would become an issue again.

I don't know what could have saved me, maybe .current_editor should be a file that your agents instructions.md file imports, and your editor updates it, to give Claude context about your tooling.