# `Puck.Eval.Inspector`
[🔗](https://github.com/bradleygolden/puck/blob/v0.2.23/lib/puck/eval/inspector.ex#L1)

Debugging tools for trajectories and evaluation results.

When evals fail, developers need human-readable output to determine if the
eval is broken or the agent is broken. Anthropic emphasizes reading transcripts
to ensure evals "feel fair".

## Example

    {output, trajectory} = Collector.collect(fn ->
      MyAgent.run("Find John")
    end)

    Inspector.print_trajectory(trajectory)
    # => Prints formatted trajectory to console

    result = Result.from_graders(output, trajectory, graders)

    if not result.passed? do
      IO.puts(Inspector.format_failures(result))
    end

# `format_failures`

Formats grader failures into a readable string.

Returns a string listing all failed graders and their reasons.
Suitable for ExUnit assertions or logging.

## Example

    result = Result.from_graders(output, trajectory, graders)

    if not result.passed? do
      IO.puts(Inspector.format_failures(result))
    end

    # Or in tests:
    assert result.passed?, Inspector.format_failures(result)

## Output Format

    2 failures:
      - Output does not contain "john@example.com"
      - 7 steps exceeds max of 5

# `print_trajectory`

Prints a human-readable trajectory to the console.

## Options

  * `:device` - IO device to print to (default: `:stdio`)
  * `:max_length` - Max characters for output display (default: 200)

## Example

    Inspector.print_trajectory(trajectory)
    # Trajectory (3 steps, 425 tokens, 1250ms)
    #
    # Step 1:
    #   Input: "Find John's email"
    #   Output: %LookupContact{name: "John"}
    #   Tokens: 150 in, 30 out (180 total)
    #   Duration: 450ms
    # ...

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*Consult [api-reference.md](api-reference.md) for complete listing*