Skill Judge

A rubric for evaluating a single skill's design quality. This is narrower than deciding whether a skill should exist (skill-curation) and than reviewing an arbitrary artifact (adversarial-review): it scores how well a given SKILL.md is built, and says exactly what to change.

The core test: knowledge delta

A skill's value = expert-only knowledge − what the model already knows.

A skill is not a tutorial. Restating what the model can already do is noise that costs context and dilutes the catalog. The valuable content is the delta: decision trees, trade-offs, non-obvious gotchas, anti-patterns, the "we learned this the hard way" judgment that isn't in the base model. Before scoring anything else, ask: what does this teach that a capable model didn't already know? If the answer is thin, no amount of polish saves it.

Dimensions to score

1. Knowledge delta (the gate) — is there real expert signal, or is it a tutorial? Cut restated basics.
2. Trigger clarity — does the description say when to use it in concrete, matchable terms (the situations, the verbs), so it actually fires at the right moment? Vague triggers = a skill that never activates.
3. Scope — one coherent capability. "And"-heavy skills should split.
4. Progressive disclosure — is the SKILL.md lean, pushing exhaustive detail into references loaded on demand, rather than front-loading everything?
5. Actionability — decisions and steps a reader can apply, not prose to admire.
6. Self-containment — no dependence on the author's private context; no secrets; renders/loads cleanly.

Output: fixes, not a grade

A bare score teaches nothing. For each weak dimension, name the specific defect and the concrete change — "the description lists capabilities but no trigger situations; add the verbs/scenarios that should invoke it" beats "trigger clarity: 2/5." Default to REVISE when the knowledge delta is thin; that's the failure that quietly fills a catalog with filler.

Adapted from the MIT-licensed softaworks/agent-toolkit skill-judge skill.