> it does that at first, then a few messages of corrections and pointers, it forgets that constraint.

Yup, most models suffer from this. Everyone is raving about million tokens context, but none of the models can actually get past 20% of that and still give as high quality responses as the very first message.

My whole workflow right now is basically composing prompts out of the agent, let them run with it and if something is wrong, restart the conversation from 0 with a rewritten prompt. None of that "No, what I meant was ..." but instead rewrite it so the agent essentially solves it without having to do back and forth, just because of this issue that you mention.

Seems to happen in Codex, Claude Code, Qwen Coder and Gemini CLI as far as I've tested.