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It passed CI. It passed your evals. The customer still got the wrong answer

It passed CI. It passed your evals. The customer still got the wrong answer

Data The New Stack
AI agents frequently return 'successful' responses that are factually wrong, necessitating end-to-end trace debugging to identify retrieval or orchestration failures.
What: Sean O'Dell argues that traditional CI/CD pipelines fail to catch logic errors in AI agents because standard tests don't validate retrieval context validity. Debugging now requires capturing end-to-end traces including retrieval inputs, model calls, and tool results, rather than just relying on faithfulness metrics.
Why it matters: The industry is moving from testing inputs/outputs to auditing the 'trajectory' of an agent, as '200 OK' statuses mask quiet failures where the model retrieves relevant but incorrect context.
Takeaway: Add `release`, `retrieval_config`, and `feature_flag` state as attributes at the root span of your AI agent's traces to enable comparison between successful and failed runs.
Deep dive
  • Agent failures are often 'quiet'—the system returns 200 OK while the user receives a wrong answer.
  • A 'faithful' answer can be wrong if the retrieved documentation context is irrelevant to the specific user requirements (e.g., wrong product version).
  • Trace data must link model calls, tool arguments, and tool results to explain why an agent followed a specific path.
  • Repeated, identical tool calls in a trace often indicate harness-level retries or orchestration logic issues, not model failures.
  • Evaluation needs to distinguish between 'relevance' (does the document contain the topic?) and 'validity' (is it correct for this request?).
  • Implement separate deterministic tests for data lookup filters—do not rely on a judge model for logic that can be verified with standard unit tests.
Decoder
  • Faithfulness (Groundedness): A metric measuring if an AI's answer is strictly supported by the provided source documents.
  • Trajectory: The sequence of model thoughts, tool calls, and tool outputs that form an agent's decision path.
  • Root Span: The top-level operation in a distributed trace that represents the entire user request.
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