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⚠️ Before You Start
Risk: Medium
Duration: 2-3 hours per agent
Last Validated: Not yet validated (draft)
Kind: Checklist
Risk Note: Medium (silent drift or a recalibrated judge hides real quality loss)

Online evaluation drift and judge-model upgrade checklist

Draft outline: not validated

Drafted with AI from official sources on 16 Oct 2026. Do not use on a live system until it is written, dry-run by someone other than the author and signed off (planned 2026-11-20). Author: Devadharshini Raja · dry-run: Yasar · sign-off: Prasanna. Work items: AGT-07-T13, AGT-07-T14, AGT-07-T15, AGT-07-T16.

1. Summary

Monthly for every production agent, and whenever the judge model is retired or upgraded. Use it when online scores move without a release.

Risk: Medium (silent drift or a recalibrated judge hides real quality loss). Typical duration: 2-3 hours per agent.

2. When to use and when not to

Use it when: Monthly for every production agent, and whenever the judge model is retired or upgraded. Use it when online scores move without a release.

Do not use it when: to be written by the author.

3. What you must know first

  • Online scores move for three reasons: user mix, upstream data or tools, and judge changes
  • A judge upgrade must be recalibrated before its scores are compared with old ones
  • Trace sampling settings change what you measure; the Azure Monitor distro samples at 5 traces per second by default
  • Trace data can contain personal data; apply the same access controls as production logs

4. Checklist

  • Confirm traces and online evaluation results arrived for every day of the period.
  • Compare the four Level 2 metrics with the last release gate results.
  • Break down any drop by task type, tool and tenant.
  • Check for tool schema, data source or model version changes in the period.
  • If the judge model changed, score the calibration set with old and new judges and record the offset.
  • Re-baseline only after the agent lead accepts the offset in writing.
  • Raise a defect for any real drop and link example traces.
  • Record the review outcome in the agent's run log.

Draft snippet: Online evaluation and judge calibration config

agent: invoice-triage-agent
online_evaluation:
  sample_rate: 0.05          # share of production runs scored by the judge
  metrics: [task_success, tool_accuracy, step_efficiency, cost_per_task_usd]
  schedule: daily
judge:
  deployment: ${JUDGE_DEPLOYMENT}
  version_pinned: true
calibration:
  dataset: eval/calibration_labelled.jsonl
  min_cases: 20
  rerun_on: [judge_upgrade, monthly_review]
alerting:
  task_success_drop: 0.03
  owner: qe-lead

Snippets to add:

  • snippets/eval/online-eval.yaml: Online evaluation sampling and calibration config (yaml)
  • snippets/docs/drift-review.md: Monthly drift review record (markdown)

5. Known issues and fixes

Symptom Likely cause Fix
Online scores drop with no release Upstream tool or data change Check tool error rates and data source change logs for the same period
Scores jump after a judge upgrade New judge is more lenient or stricter Score the calibration set with both judges and apply the offset before comparing
Gaps in daily metrics Sampling or exporter misconfiguration Check sampling_ratio or traces_per_second and exporter errors in the app logs
Traces show user personal data Content recording left on Disable or redact content capture and purge per retention policy

6. Monitoring and alerts

Signal Alert when Action
Online task success (7-day average) Drops more than the release tolerance below baseline Run this checklist within 2 working days
Trace ingestion for the agent No traces for 30 minutes during business hours Check exporter configuration and the Application Insights connection

7. AWS and open-source equivalents

AgentCore online evaluations score sampled production traces on AWS. Open-source stacks combine OpenTelemetry traces with scheduled DeepEval or LangSmith runs on sampled data.

8. Validation record

Pending. Planned dry-run scenario: A second engineer runs the checklist on the sandbox agent after swapping the judge deployment. Pass: the offset is measured on the calibration set, the drift record is complete and no baseline is changed without sign-off.

9. Sources