Issue 12

3 min read

Test every layer that makes the decision.

This week’s strongest work tests the evaluation system itself: the judge’s behavior, the rules behind its verdict, and the monitoring path around an agent. Start with SANE, which builds scorer-specific stress tests instead of reusing a generic test library.

A judge needs tests built for its exact rule.

Published Oct 20, 2026Read first

What it saysSANE reads a judge’s specification and creates controlled changes that should preserve or move its score. Across five criteria it produced 77 validated test families versus 21 for a fixed-library baseline. Its faithfulness tests ranked 11 judges similarly to a human-labeled benchmark (Spearman correlation 0.852 versus 0.100).

Why it mattersAverage agreement can hide brittle behavior. A targeted test tells you whether a judge reacts correctly when the exact thing it claims to measure changes—or stays the same.

Try thisChoose one judge. Write one change that should preserve its verdict and one that should reverse it, then run both before the next release.

How to use it

Suggested steps

  1. State the judge’s criterion and output contract plainly.
  2. Create paired examples with an expected same, higher or lower score.
  3. Validate the changes independently before counting a judge failure.
Conceptual judge stress testsConceptual explanation · Evals Weekly
Controlled changeExpected behavior
Paraphrase onlyScore stays stable
Add grounded supportFaithfulness score rises
Repeat the same inputVerdict remains consistent

Keep in mind Generated recipes and cases were validated by model panels, not people. Human alignment was tested only through judge rankings on faithfulness, not case-by-case or across the other four criteria.

A quick check for yourself

What makes a useful judge stress test?

Show answer

A controlled input change with an independently justified expected score relation.

Open post
Source & why it’s here

SANE: Automated Scorer-Specific Metamorphic Testing for LLM Judges (opens in a new tab)

Read first: the most direct and reusable method this week for testing whether an AI judge behaves like a measurement instrument.

Case-specific rules can outperform a generic safety label.

Published Oct 21, 2026

What it saysOn 236 human-labeled responses, three rule-guided judges reached 89.4%–95.3% agreement, compared with 80.5%–87.3% for generic prompts. Each prompt’s scoring guide separated prohibited behavior, allowed exceptions and usefulness instead of asking for one broad safe-or-unsafe verdict.

Why it mattersA named policy category is not enough guidance for borderline cases. Concrete rules and exceptions make disagreements easier to diagnose and reduce the chance that caution simply replaces usefulness.

Try thisFor one high-risk intent, write the prohibited behavior, valid exceptions and minimum useful response as separate checks.

How to use it

Suggested steps

  1. Translate the policy into observable yes-or-no items.
  2. Keep safety and usefulness as separate outputs.
  3. Compare the judge with expert labels, including borderline exceptions.
Conceptual prompt-level rubricConceptual explanation · Evals Weekly
Separate checkQuestion
Prohibited behaviorDid the response enable the named harm?
Allowed exceptionDoes a policy exception apply?
UsefulnessDid the safe response still help?

Keep in mind The prompts were synthetic and the tested systems were locally served open-weight models without production safeguards. The study covers dialogue, not tool-using agents, and model-generated rule specifications may miss rare risks.

A quick check for yourself

Why score safety and usefulness separately?

Show answer

A refusal can be safe yet unhelpful; one label hides that trade-off.

Open post
Source & why it’s here

Coverage counts do not prove a monitor is unavoidable.

Published Oct 22, 2026

What it saysDuring a three-week high-access assessment, external evaluators found several routes around a historical agent-monitoring system, including one that could hide hundreds of recent actions and another caused by differences between the context seen by the agent and monitor.

Why it mattersA strong classifier is only one link. Routing, serialization, logging, tool coverage and isolation can silently decide whether the monitor sees the event at all.

Try thisFor one day of agent traffic, reconcile every eligible event against monitor logs and investigate every missing record.

How to use it

Suggested steps

  1. Inventory every route that can create agent or tool traffic.
  2. Verify that agent and monitor receive equivalent context.
  3. Test that agent actions cannot delay, disable or alter monitoring.
Conceptual monitoring auditConceptual explanation · Evals Weekly
LayerEvidence to reconcile
Traffic ledgerWhich events should be monitored?
Monitor inputDid it see the same relevant context?
Incident pathWas a flagged event stored and owned?

Keep in mind The public post is a limited, partly redacted account of the system as it existed on or before July 21. OpenAI says production-impacting findings were patched, but the external evaluators did not verify those fixes.

A quick check for yourself

Can high monitor accuracy protect events the monitor never receives?

Show answer

No. Coverage and routing must be tested separately from verdict quality.

Open post
Source & why it’s here

Red-Teaming OpenAI's Internal Agent Monitoring Systems (opens in a new tab)

Third: a rare practical look at evaluating the monitoring infrastructure around real agent systems.

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