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The LLM Eval Rubric Generator

Generate a set of automatic pass/fail eval checks for any prompt — schema-match, contains, regex, length, and is-valid-json — so a bad prompt edit or a silent model regression gets caught before your customers do.

▹ The LLM Eval Rubric Generator — copy & paste
# The LLM Eval Rubric Generator — a free tool by VernaOne (https://verna.one)
# Paste this whole prompt into ChatGPT, Claude, or Gemini, then describe your prompt/task at the bottom.

You are a QA engineer for LLM systems. For the prompt or task described at the bottom, write an **eval rubric**: a set of automatic, machine-checkable pass/fail checks that grade any output of that prompt.

Rules for the rubric:
- Prefer machine-checkable check types only: `is-valid-json`, `schema-match`, `contains`, `not-contains`, `regex`, `length`, `equals`, `one-of`.
- Each check must be specific enough that code could decide pass/fail with no human judgment.
- Cover three layers: (a) **format** — is the output shaped correctly; (b) **content** — does it contain / avoid the right things; (c) **safety** — refusal and guardrail behavior.
- 5–8 checks total. No vague or subjective checks ("is it good?"). If a subjective quality matters, convert it into a concrete proxy (e.g., "contains a numbered list of 3–5 items" → length + regex).

Output exactly this, and nothing else:

## Eval rubric
A table, one row per check:
| # | Check type | Target (field / whole output) | Condition | Why it matters |

## Machine-readable rules
The same checks as a JSON array, each: `{ "type": "...", "target": "...", "condition": "...", "severity": "error" | "warning" }`. `error` = must pass; `warning` = should pass.

## Edge cases to add later
2–4 tricky inputs worth adding as fixtures (e.g., empty input, very long input, adversarial input), one line each.

Rules:
- If the task doesn't specify an output format, assume the most likely one and note the assumption in one line before the rubric — do not ask me questions.
- Keep it tight. No filler.

---
DESCRIBE THE PROMPT / TASK TO EVALUATE (and paste an example output if you have one):
{{DESCRIBE YOUR PROMPT OR TASK HERE}}

↑ The header line (with the verna.one link) travels with the prompt when you share it.

How to use it

  1. Copy the prompt and paste it into ChatGPT, Claude, or Gemini.
  2. Describe your prompt or task at the bottom (paste an example output if you have one).
  3. Get a rubric of machine-checkable checks, plus a JSON version and edge cases to test.
  4. Attach the checks to your prompt in VernaOne so they run on every execution.

Run it for real, not just once

VernaOne turns the result into a versioned, model-agnostic endpoint with automatic fallback across every provider — call one name, change models without changing code.

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Frequently asked

What is an LLM eval?

An eval is an automatic check that grades a model's output pass or fail against a rule — for example, that the output is valid JSON, matches a schema, contains a required phrase, follows a regex, or stays within a length. Running evals on every output catches regressions from a prompt edit or a model change before they reach customers.

What makes a good eval rubric?

Machine-checkable rules beat vague ones. Prefer schema-match, contains, regex, length, and is-valid-json over subjective judgments, and make each check specific enough that code can decide pass/fail with no human in the loop. This prompt generates exactly that kind of rubric for your task.

How do I run these checks on every call?

You attach them to the prompt so they run automatically. In VernaOne you add eval rules to a prompt version, and every execution is graded pass/fail with the result stored — so a bad prompt edit or a silent model regression is flagged instead of shipping. This free prompt gives you the rubric to attach.

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