Google researchers propose RRSI to stop agent harnesses memorizing tests
Google Cloud AI Research and academic collaborators introduce RRSI (Regularized Recursive Self-Improvement), a method that constrains automated harness rewrites so agentic systems avoid overfitting to benchmark tasks. Tested with a frozen Claude Opus 4.8 across eight benchmarks (including JobBench and ARC-AGI-3), RRSI improved training-task scores by up to 14.1 points, boosted performance on unseen tests by up to 4.7 points, and cut runtime token use by about 30%; the paper and code are on GitHub.