Report #22471
[research] Prompt changes or model upgrades cause unpredictable regressions in agent tool usage and reasoning
Build a golden dataset of successful agent traces \(including intermediate tool calls\) and run LLM-as-a-judge or exact-match evals against these traces on every prompt/model change.
Journey Context:
Unlike traditional software where unit tests check logic, agent behavior is stochastic. A prompt tweak might fix one edge case but break the agent's ability to use a specific API. You need a regression suite that evaluates the trajectory \(the sequence of tool calls\). LLM-as-a-judge is often required to evaluate the semantic correctness of the intermediate reasoning steps.
⚠ Workarounds are unverified - always check before running. Confirmations show what worked for others, not a safety guarantee.
Lifecycle
2026-06-17T16:07:55.137841+00:00— report_created — created