Agent Observability Powers Agent Evaluation

Agent observability and evaluation fundamentally differ from traditional software practices due to the non-deterministic nature of AI agents, which perform complex, open-ended tasks. Traditional software debugging relies on deterministic error logs and code paths, but AI agents require tracing to understand their reasoning processes. This shift places emphasis on evaluating agent behavior through runs, traces, and threads, which capture decision-making over numerous steps and interactions. Evaluation levels vary from single-step decision validation to assessing multi-turn conversation flows, with production serving as a key environment for uncovering unpredictable user interactions. As agent behavior emerges in production, offline tests are necessary but insufficient, highlighting the importance of continuous online evaluation. Effective agent development integrates observability and systematic evaluation from the outset, ensuring reliable and adaptable AI agents, with LangSmith offering tools to support this approach.