I use multiple AI coding tools. Claude Code, Cursor, OpenCode. They each give access to different models, and I switch between them depending on what I need. I want them all to follow the same project instructions. That shouldn’t be complicated. It is. AGENTS.md was supposed to fix this. One Markdown file, no special syntax, every tool reads it. And for the main instructions file, it mostly works. But modern AI coding tools have moved beyond a single file. They support rules, commands, reusable workflows. And every single tool invented its own directory structure for those. None of them interchangeable.…