eval
An eval is a structured test that measures how well an AI model or AI agent performs, using defined tasks and scoring criteria.
Eval, short for evaluation, refers to testing an AI model or AI agent on defined tasks and scoring the results to measure performance as a number. The word can also mean a suite that bundles many such tasks.
In AI development, teams rerun the same evals whenever they change a model, prompt or agent setup, comparing scores to confirm improvements and analyzing failed tasks to find what to fix. Unlike public standardized benchmarks, evals are often built in-house for a specific product or workflow.
This entry is based on AIPOST articles and widely known facts. If something is wrong, please send us a correction request.
Articles covering this entry
The standard answer in 2025 was LLM-as-a-judge evaluation, or evals: a language model grades each trace against defined criteria and returns both a verdict, suc…
…oops The agent emits traces and spans, records of each run and of each step inside it, eval suites score them, and engineers fix failure modes one after another