Preprint Open access
MESH-Harness: Self-Improving Agent Harnesses via Bandit-Guided Compositional Evolution
An agent harness is the code that organizes context, maintains state, and coordinates tool calls for a language model. We study how to improve the harness under a limited evaluation budget while keeping model weights fixed. Our method, MESH-Harness, organizes each harness into functional modules with explicit role-spec …