Evaluates Claude Agent Skills on 10 quality axes with letter grades (A+ through F) and specific improvement recommendations. Use when auditing a skill, comparing skills, prioritizing improvements, or performing quality control on a skill library. Activate on "grade skill", "evaluate skill", "skill quality", "skill audit", "skill review", "rate skill". NOT for creating skills (use skill-architect), grading code quality, or evaluating non-skill documents.
Instrucciones de origen · Vista previa de solo lectura
name
skill-grader
license
Apache-2.0
description
Evaluates Claude Agent Skills on 10 quality axes with letter grades (A+ through F) and specific improvement recommendations. Use when auditing a skill, comparing skills, prioritizing improvements, or performing quality control on a skill library. Activate on "grade skill", "evaluate skill", "skill quality", "skill audit", "skill review", "rate skill". NOT for creating skills (use skill-architect), grading code quality, or evaluating non-skill documents.
allowed-tools
Read,Grep,Glob
argument-hint
[skill-path]
metadata
{"category":"Productivity & Meta","tags":["grader","grade-skill","evaluate-skill","skill-quality"],"pairs-with":[{"skill":"skill-architect","reason":"Grading reveals architectural gaps that the architect addresses with structural improvements"},{"skill":"skill-creator","reason":"Grading feedback guides creators on which quality axes need improvement"},{"skill":"skill-coach","reason":"Grading provides objective scores that coaching uses to prioritize improvement areas"}]}
Structured evaluation rubric for Claude Agent Skills. Produces letter grades (A+ through F) on 10 axes plus an overall grade, with specific improvement recommendations for each axis.
Designed for sub-agents and non-expert reviewers who need a mechanical, repeatable process for assessing skill quality without deep domain expertise.
When to Use
✅ Use for:
Auditing a single skill's quality
Comparing skills against each other
Prioritizing which skills to improve first
Quality control sweeps across a skill library
Generating improvement roadmaps
❌ NOT for:
Creating new skills (use skill-architect)
Grading code quality or non-skill documents
Evaluating agent performance (different from skill quality)
Grading Process
flowchart TD
A[Read SKILL.md + all files] --> B[Score each of 10 axes]
B --> C[Assign letter grade per axis]
C --> D[Compute overall grade]
D --> E[Write improvement recommendations]
E --> F[Produce grading report]
Step-by-Step
Read the entire skill folder — SKILL.md, all references, scripts, CHANGELOG, README
Score each axis — Use the rubric below (0-100 per axis)
Convert to letter grade — See grade scale
Compute overall grade — Weighted average (Description and Scope are 2x weight)
Write 1-3 specific improvements per axis scoring below B+
Produce the grading report in the output format below
The 10 Evaluation Axes
Axis 1: Description Quality (Weight: 2x)
Does the description follow [What] [When] [Keywords]. NOT for [Exclusions]?
Grade
Criteria
A
Specific verb+noun, domain keywords users would type, 2-5 explicit NOT exclusions, 25-50 words
B
Has keywords and NOT clause, but slightly vague or missing synonym coverage
C
Too generic, missing NOT clause, or >100 words of process detail
D
Single vague sentence ("helps with X") or name/description mismatch
F
Missing or empty description
Axis 2: Scope Discipline (Weight: 2x)
Is the skill narrowly focused on one expertise type, or a catch-all?
Grade
Criteria
A
One clear expertise domain, "When to Use" and "NOT for" sections both present and specific
B
Mostly focused, minor boundary ambiguity
C
Covers 2-3 related but distinct domains, should probably be split
D
Catch-all skill ("helps with anything related to X")
F
No scope boundaries defined at all
Axis 3: Progressive Disclosure
Does the skill follow the three-layer architecture (metadata → SKILL.md → references)?
Grade
Criteria
A
SKILL.md <300 lines, heavy content in references, reference index in SKILL.md with 1-line descriptions
B
SKILL.md <500 lines, some references used, index present
C
SKILL.md >500 lines, or all content inlined with no references
D
SKILL.md >800 lines, or references exist but aren't indexed in SKILL.md
F
Single massive file with no structure
Axis 4: Anti-Pattern Coverage
Does the skill encode expert knowledge that prevents common mistakes?
Grade
Criteria
A
3+ anti-patterns with Novice/Expert/Timeline template, LLM-mistake notes
B
1-2 anti-patterns with clear explanation
C
Anti-patterns mentioned but no structured template
D
No anti-patterns, just positive instructions
F
Contains advice that IS an anti-pattern (outdated, harmful)
Axis 5: Self-Contained Tools
Does the skill include working tools (scripts, MCPs, subagents)?
Grade
Criteria
A
Working scripts with CLI interface, error handling, dependency docs; OR valid "no tools needed" justification
B
Scripts exist and work but lack error handling or docs
C
Scripts referenced but are templates/pseudocode
D
Phantom tools (SKILL.md references files that don't exist)
F
References non-existent tools AND no acknowledgment
Note: Not every skill needs tools. A pure decision-tree skill can score A if tools aren't applicable.
Axis 6: Activation Precision
Would the skill activate correctly on relevant queries and stay silent on irrelevant ones?
Grade
Criteria
A
Description has specific keywords matching user language, clear NOT clause, no obvious false-positive vectors
B
Good keywords, minor false-positive risk
C
Generic keywords that overlap with other skills
D
No specific keywords, or NOT clause contradicts intended use
F
Description would cause constant false activation
Axis 7: Visual Artifacts
Does the skill use Mermaid diagrams, code examples, and tables effectively?
Grade
Criteria
A
Decision trees as Mermaid flowcharts, tables for comparisons, code examples for concrete patterns
B
Some diagrams or tables, but key decision trees still in prose
C
Tables used but no Mermaid diagrams for processes
D
Prose-only, no visual structure
F
Wall of text with no formatting aids
Axis 8: Output Contracts
Does the skill define what it produces in a format consumable by other agents?
Grade
Criteria
A
Explicit output format (JSON schema, markdown template, or structured sections), subagent-consumable
B
Output format implied but not explicitly documented
C
No output format, but content is structured enough to infer
D
Unstructured prose output expected
F
N/A (pure reference skill) — exempt from this axis
Axis 9: Temporal Awareness
Does the skill track when knowledge was current and what has changed?
Grade
Criteria
A
Timelines in anti-patterns, "as of [date]" markers, CHANGELOG with dates
B
Some temporal context, CHANGELOG exists
C
No dates on knowledge, but CHANGELOG exists
D
No temporal context anywhere, knowledge could be stale
F
Contains demonstrably outdated advice without warning
Axis 10: Documentation Quality
README, CHANGELOG, and reference organization.
Grade
Criteria
A
README with quick start, CHANGELOG with dated versions, references well-organized with clear filenames
B
README and CHANGELOG exist, references present
C
SKILL.md is the only file, but it's well-structured
D
No README, no CHANGELOG, disorganized references
F
SKILL.md is the only file and it's poorly structured
Grade Scale
Letter
Score Range
Meaning
A+
97-100
Exemplary — sets the standard
A
93-96
Excellent — minor improvements possible
A-
90-92
Very good — a few small gaps
B+
87-89
Good — notable room for improvement
B
83-86
Solid — several areas need work
B-
80-82
Above average — meaningful gaps
C+
77-79
Average — significant improvements needed
C
73-76
Below average — major gaps
C-
70-72
Barely adequate
D+
67-69
Poor — fundamental issues
D
63-66
Very poor — needs major rework
D-
60-62
Near-failing quality
F
<60
Failing — start over
Overall Grade Computation
Axes 1 (Description) and 2 (Scope) carry 2x weight. All others carry 1x weight. If Axis 8 (Output Contracts) is marked exempt, remove it from the calculation.
Wrong: Giving B+ because "it's pretty good" without checking criteria.
Right: Match observations to the rubric table literally. If the description lacks a NOT clause, it cannot score above C on Axis 1.
Missing Context
Wrong: Grading a pure decision-tree skill poorly on Axis 5 (tools) because it has no scripts.
Right: Mark Axis 5 as "A — tools not applicable for this skill type."
Ignoring Phantoms
Wrong: Scoring Axis 5 as B because scripts are "referenced."
Right: Actually check if every referenced file exists. If scripts/validate.py is mentioned but doesn't exist, that's D.
Output Contract
This skill produces:
10-axis grade report with letter grades (A+ through F) and weighted total
Per-axis feedback with specific evidence and improvement suggestions
Priority improvements ranked by impact on overall quality score
Before/after comparison projecting grade changes from recommended fixes
