arXiv cs.AIPaper
Co-Evolving Harnesses and Models: On-Policy Correction Helps Weaker Models Catch Up Where Imitation Fails
This is a counterintuitive finding that matters for anyone scaling agents beyond frontier models. The core tension is real: scaffolding and weights are both knobs, but they don't always turn in sync. If you're trying to use smaller models for cost, this tells you to evolve your harness first with the model you have, then consider whether expert-trajectory imitation will help or hurt. The negative results are more valuable than the positive ones because they redirect effort away from a plausible but failing approach.