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Evaluation Harness (Agent)

Reviewed 19 July 2026Canonical definitionPart of: Agent Evaluation Terms →

An agent evaluation harness is the test infrastructure that automatically runs an agent against a suite of benchmark tasks, captures outputs, scores them against defined criteria, and generates performance reports. It is the CI layer for agent quality, running on every code or prompt change to catch regressions before they reach production. A mature evaluation harness covers accuracy, latency, cost, tool-call correctness, and safety-policy adherence.

Looking for the applied side? Read What is an eval harness and how to build one.

§01 / QUESTIONSterm: Evaluation Harness (Agent)
Questions

Common questions.

What is Evaluation Harness (Agent)?

An agent evaluation harness is the test infrastructure that automatically runs an agent against a suite of benchmark tasks, captures outputs, scores them against defined criteria, and generates performance reports.

How is Evaluation Harness (Agent) used in production?

It is the CI layer for agent quality, running on every code or prompt change to catch regressions before they reach production. A mature evaluation harness covers accuracy, latency, cost, tool-call correctness, and safety-policy adherence.

Which terms are related to Evaluation Harness (Agent)?

Closely related concepts include Prompt Regression Testing, Agent Trajectory, Continuous Integration Agent, Quality Gate (AI). Each is defined in the Prefactor glossary.

Where can I read more about Evaluation Harness (Agent) in practice?

The guide "What is an eval harness and how to build one" covers the applied side in depth.

§02 / RELATEDnext: where this fits

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