# Evaluating Agents: Trajectories, Tools and Outcomes — LangGraph Agents & Multi-Agent Systems

Source: https://www.geekswithgeeks.com/en/langgraph-agents/t-eval

> Judge not only the final answer but the path taken.

## Right answer, wrong way is a failure too

Agents can reach the right answer by an unsafe or wasteful path, or the wrong answer after a good one. Evaluate at three levels: **outcome** (is the final answer or end state correct and grounded?), **trajectory** (were the right tools called, in a sensible order, with correct arguments, in few steps?) and **efficiency and safety** (tokens, cost, latency, no forbidden actions, approvals respected). Build a dataset of realistic tasks with expected outcomes and, where useful, expected tool sequences; include adversarial and unanswerable cases. Use traces (for example LangSmith or any OpenTelemetry-compatible tool) to inspect failures, and re-run the suite on every prompt, tool or model change.

**Quiz:** Why evaluate the trajectory and not just the final answer?

- [x] An agent can be right for the wrong or unsafe reasons
- [ ] Trajectories are shorter
- [ ] Final answers are never useful
- [ ] It avoids tracing

*Answer:* An agent can be right for the wrong or unsafe reasons. The path reveals wasted steps, wrong tools and policy violations.