The Eval Suite That Became the Spec Nobody Agreed To
Open any mature agent codebase and ask a simple question: where is the requirements document? Not the pitch deck, not the launch doc, not the Notion page that was last touched in Q3. Where is the artifact that says, concretely and unambiguously, what this agent is supposed to do?
For most teams, the honest answer is the eval suite. There is a folder of test cases — inputs paired with expected outputs, rubrics, judge prompts — and a CI gate that says pass or fail. That folder is the only place where "correct" is defined precisely enough to be executed. Everything else is prose, and prose drifts.
This is not inherently bad. An executable spec is more honest than a PRD that nobody reads. The problem is that almost nobody treats the eval suite as a spec. It was assembled by one engineer, under deadline, to make a release gate go green. It encodes a hundred judgment calls that were never written down, never reviewed, and never agreed to. And the model is now optimized precisely to it.
