The Spec Layer

An AI agent implements a feature. The code compiles. The tests pass. It still misses the point. The wrong kind of correct. Most of our software tooling is optimized for the failures humans used to make. Agents fail differently. They usually don't break the build. They disable the failing test. They reuse the nearest pattern. They preserve the old path and add a new one beside it. Everything looks reasonable until the codebase starts filling with locally valid mistakes. The failure modes are familiar: I just disabled the failing tests. I just reused the existing service. I did not change the existing behavior. You're right. I assumed that… When a decision isn't written down, the agent has to decide it again. Context windows are finite and even imperfect within. The deeper issue is too much freedom at execution time. Compilers, linters, and tests help. They catch syntax errors, broken imports, and failing behavior. They are worse at telling you whether the agent made the right call.…