LLM-as-judge evaluation rubric
A judge prompt with binary criteria, so scores are repeatable rather than impressionistic. Written for Claude, free to copy, with every placeholder explained below.
The prompt
<role>
You are an evaluator applying a fixed rubric. You are not the author and you do not
reward effort.
</role>
<task_being_evaluated>
{{original_task}}
</task_being_evaluated>
<output_to_evaluate>
{{output}}
</output_to_evaluate>
<rubric>
{{criteria}}
</rubric>
<constraints>
- Answer each criterion strictly yes or no. No partial credit, no "mostly".
- For each, quote the specific text that decided the answer. If you cannot quote
anything, the answer is no.
- Judge only against the rubric. Ignore anything you would have done differently.
- Do not reward length. A shorter output that meets every criterion scores higher
than a longer one that does not.
- Do not reward writing style unless the rubric mentions it.
</constraints>
<output_format>
Return only JSON:
{"criteria": [{"id": string, "pass": boolean, "evidence": string}], "score": number, "summary": string}
</output_format>
Now evaluate the output.Open this in the prompt builder to adapt it, score it, and re-render it for a different model.
What to replace
| Placeholder | What to put there |
|---|---|
| {{original_task}} | The prompt the output was produced from. |
| {{output}} | The output being judged. |
| {{criteria}} | Numbered criteria, each answerable yes or no. |
Why this prompt works
- Binary criteria only
- Partial credit is where judge inconsistency lives. Yes-or-no answers with quoted evidence are repeatable across runs.
- Length bias named and forbidden
- Model judges systematically prefer longer answers. Naming the bias measurably reduces it.
- Evidence required per criterion
- "If you cannot quote anything, the answer is no" converts a vague impression into a defensible verdict.
- Style excluded unless in the rubric
- Judges reward prose resembling their own. Excluding style keeps the evaluation on the thing being measured.
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- Rewrite for clarity without changing meaning — Tighten prose while keeping the author's voice and every factual claim intact.
- Summarise a document without distorting it — A summary that separates what the source says from what it implies.
- Code review for correctness only — Findings with a triggering input, ranked by severity — and permission to find nothing.
Browse the full prompt library, all ai, agents & prompting prompts, or read the guides.