Agent instructions - why they drift from the project and how to catch it
You write the rules file for your AI once, and the agent works from it for months - including the months after half the rules stop being true. In the METR study from early 2025, experienced developers using AI were 19% slower, while feeling 20% faster. In this post I show how I solved it for myself. The instructions came under the same scrutiny as code, they got a gate of their own, and the gate got a test that checks it.
