Evaluating Frontier Models: Native vs Third-Party Harnesses
xeophon · x · 2026-07-20
Discusses the selection of testing harnesses when evaluating the capabilities of frontier models, especially for CBRN threats.
- Industry Trend: The default recommendation is to use the native harness provided by the model vendor.
- Counter-intuitive Finding: Some models actually perform worse in their native harness compared to third-party tools like Pi or Cursor.
- Security Evaluation Advice: To maximize model performance and expose true limits, evaluators must find the optimal harness for each model, as bad actors won't limit themselves to standard ReAct loops.
Related event: Evaluating Frontier Models: Harness Choice and Token Limits(3 posts)→
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