> Seems like the progressive disclosure approach is the best for context efficiency; I wound up with a somewhat tight generic AGENTS.md, and the .cursor/rules individual files with glob matching for file names. Cursor honored those well.

This is also generally where I've landed - keep the AGENTS.md super light, and link out to docs as needed. Same idea with skills as well. Basically, preserve the context window at all costs.

The part I'm curious about is, when we're making the sorts of behavior changes you're describing on shared repos, how do we actually measure and quantify impact? It's one thing to tell the team that the agent should perform better, and it's another to say that you made the agent 5% better across a variety of tasks for every dev in the repo.