Skill Evaluator

Skill Evaluator (WIP)

Evaluates skills against Anthropic's official best practices for agent skill authoring. Produces structured evaluation reports with scores and actionable recommendations.

Quick Start

1. Read the skill's SKILL.md and understand its purpose
2. Run automated validation: scripts/validate_skill.py
3. Perform manual evaluation against criteria below
4. Generate evaluation report with scores and recommendations

Evaluation Workflow

Step 1: Automated Validation

Run the validation script first:

scripts/validate_skill.py 

This checks:

• SKILL.md exists with valid YAML frontmatter
• Name follows conventions (lowercase, hyphens, max 64 chars)
• Description is present and under 1024 chars
• Body is under 500 lines
• File references are one-level deep

Step 2: Manual Evaluation

Evaluate each dimension and assign a score (1-5):

A. Naming (Weight: 10%)

| Score | Criteria | |-------|----------| | 5 | Gerund form (-ing), clear purpose, memorable | | 4 | Descriptive, follows conventions | | 3 | Acceptable but could be clearer | | 2 | Vague or misleading | | 1 | Violates naming rules |

Rules: Max 64 chars, lowercase + numbers + hyphens only, no reserved words (anthropic, claude), no XML tags.

Good: processing-pdfs, analyzing-spreadsheets, building-dashboards Bad: pdf, my-skill, ClaudeHelper, anthropic-tools

B. Description (Weight: 20%)

| Score | Criteria | |-------|----------| | 5 | Clear functionality + specific activation triggers + third person | | 4 | Good description with some triggers | | 3 | Adequate but missing triggers or vague | | 2 | Too brief or unclear purpose | | 1 | Missing or unhelpful |

Must include: What the skill does AND when to use it. Good: "Extracts text from PDFs. Use when working with PDF documents for text extraction, form parsing, or content analysis." Bad: "A skill for PDFs." or "Helps with documents."

C. Content Quality (Weight: 30%)

| Score | Criteria | |-------|----------| | 5 | Concise, assumes Claude intelligence, actionable instructions | | 4 | Generally good, minor verbosity | | 3 | Some unnecessary explanations or redundancy | | 2 | Overly verbose or confusing | | 1 | Bloated, explains obvious concepts |

Ask: "Does Claude really need this explanation?" Remove anything Claude already knows.

D. Structure & Organization (Weight: 25%)

| Score | Criteria | |-------|----------| | 5 | Excellent progressive disclosure, clear navigation, optimal length | | 4 | Good organization, appropriate file splits | | 3 | Acceptable but could be better organized | | 2 | Poor organization, missing references, or bloated SKILL.md | | 1 | No structure, everything dumped in SKILL.md |

Check:

• SKILL.md under 500 lines
• References are one-level deep (no nested chains)
• Long reference files (>100 lines) have table of contents
• Uses forward slashes in all paths

E. Degrees of Freedom (Weight: 10%)

| Score | Criteria | |-------|----------| | 5 | Perfect match: high freedom for flexible tasks, low for fragile operations | | 4 | Generally appropriate freedom levels | | 3 | Acceptable but could be better calibrated | | 2 | Mismatched: too rigid or too loose | | 1 | Completely wrong freedom level for the task type |

Guideline:

• High freedom (text): Multiple valid approaches, context-dependent
• Medium freedom (parameterized): Preferred pattern exists, some variation OK
• Low freedom (specific scripts): Fragile operations, exact sequence required

F. Anti-Pattern Check (Weight: 5%)

Deduct points for each anti-pattern found:

• [ ] Too many options without clear recommendation (-1)
• [ ] Time-sensitive information with date conditionals (-1)
• [ ] Inconsistent terminology (-1)
• [ ] Windows-style paths (backslashes) (-1)
• [ ] Deeply nested references (more than one level) (-2)
• [ ] Scripts that punt error handling to Claude (-1)
• [ ] Magic numbers without justification (-1)

Step 3: Generate Report

Use this template:

# Skill Evaluation Report: [skill-name]

## Summary
- **Overall Score**: X.X/5.0
- **Recommendation**: [Ready for publication / Needs minor improvements / Needs major revision]

## Dimension Scores
| Dimension | Score | Weight | Weighted |
|-----------|-------|--------|----------|
| Naming | X/5 | 10% | X.XX |
| Description | X/5 | 20% | X.XX |
| Content Quality | X/5 | 30% | X.XX |
| Structure | X/5 | 25% | X.XX |
| Degrees of Freedom | X/5 | 10% | X.XX |
| Anti-Patterns | X/5 | 5% | X.XX |
| **Total** | | 100% | **X.XX** |

## Strengths
- [List 2-3 things done well]

## Areas for Improvement
- [List specific issues with actionable fixes]

## Anti-Patterns Found
- [List any anti-patterns detected]

## Recommendations
1. [Priority 1 fix]
2. [Priority 2 fix]
3. [Priority 3 fix]

## Pre-Publication Checklist
- [ ] Description is specific with activation triggers
- [ ] SKILL.md under 500 lines
- [ ] One-level-deep file references
- [ ] Forward slashes in all paths
- [ ] No time-sensitive information
- [ ] Consistent terminology
- [ ] Concrete examples provided
- [ ] Scripts handle errors explicitly
- [ ] All configuration values justified
- [ ] Required packages listed
- [ ] Tested with Haiku, Sonnet, Opus

Score Interpretation

| Score Range | Rating | Action | |-------------|--------|--------| | 4.5 - 5.0 | Excellent | Ready for publication | | 4.0 - 4.4 | Good | Minor improvements recommended | | 3.0 - 3.9 | Acceptable | Several improvements needed | | 2.0 - 2.9 | Needs Work | Major revision required | | 1.0 - 1.9 | Poor | Fundamental redesign needed |

References

• [references/evaluation-criteria.md](references/evaluation-criteria.md) - Detailed evaluation criteria with examples
• [references/scoring-rubric.md](references/scoring-rubric.md) - Complete scoring rubric and edge cases

Examples

See [evaluations/](evaluations/) for example evaluation scenarios.

Source & license

This open-source skill is cataloged on AgentStack and links to its original source — we do not rehost the code.

• Author: gotalab
• Source: gotalab/skillport
• License: MIT

Install and usage instructions live in the source repository linked above.