HarnessDev: Can LLMs Create and Evolve Their Own Agent Harness?

Benchmark Model Rank Results
code-generation-on-terminal-bench-2-1HarnessDev Creation (Gemini 3.1 Pro High) (HarnessDev generated harness)–Accuracy: 68.8
deep-research-agents-on-browsecompHarnessDev Creation (GPT-5.5 creator, Gemini 3.1 Pro executor)–Accuracy: 55.4