LESSON 7.5 · Engineering · 130 min

Agent evaluation: from final answers to trajectories

Agent evaluation: from final answers to trajectories. Learn task success, trajectories, tool errors, cost, and latency and complete: Build a 30-task regression suite. Part of the “

Learning objectives

  1. Explain what problem “Agent evaluation: from final answers to trajectories” solves without hiding behind terminology.
  2. Trace the variables and causal links across task success, trajectories, tool errors.
  3. Complete “Build a 30-task regression suite” and judge the result with evidence rather than intuition.

Core concepts

task success

task success is part of the lesson’s causal model. State its inputs, outputs, invariants, and failure mode; then verify it with a hand-check or a minimal experiment before moving to an optimized implementation.

trajectories

trajectories is part of the lesson’s causal model. State its inputs, outputs, invariants, and failure mode; then verify it with a hand-check or a minimal experiment.

tool errors

tool errors is part of the lesson’s causal model. State its inputs, outputs, invariants, and failure mode; then verify it with a hand-check or a minimal experiment.

cost

cost is part of the lesson’s causal model. State its inputs, outputs, invariants, and failure mode; then verify it with a hand-check or a minimal experiment.

and latency

and latency is part of the lesson’s causal model. State its inputs, outputs, invariants, and failure mode; then verify it with a hand-check or a minimal experiment.

Build and verify

Build a 30-task regression suite

  • Predict: write the expected output, trend, or failure before running code.
  • Build: implement only the minimum components needed to answer the question.
  • Verify: compare with a baseline or trusted implementation; save seeds, parameters, and raw outputs.
  • Transfer: change one shape, dataset, scale, or workload condition and explain whether the conclusion still holds.

Open the complete interactive lesson