evaluate-skills

What this skill does

# Claude Code Skill Evaluator

Systematically evaluate Claude Code skills for quality, compliance with best practices, and optimization opportunities. Provides detailed assessment with actionable suggestions for improvement.

## Table of Contents

- [Instructions](#instructions)
  - [1. Find Skill](#1-find-skill)
  - [2. Read the Skill File](#2-read-the-skill-file)
  - [3. Analyze Against Best Practices](#3-analyze-against-best-practices)
    - [Dimension 1: Size & Length](#dimension-1-size--length)
    - [Dimension 2: Token Economy](#dimension-2-token-economy)
    - [Dimension 3: Degrees of Freedom](#dimension-3-degrees-of-freedom)
    - [Dimension 4: Scope Definition](#dimension-4-scope-definition)
    - [Dimension 5: Description Quality](#dimension-5-description-quality)
    - [Dimension 6: Structure & Organization](#dimension-6-structure--organization)
    - [Dimension 7: Examples](#dimension-7-examples)
    - [Dimension 8: Anti-Pattern Detection](#dimension-8-anti-pattern-detection)
    - [Dimension 9: Prompt Engineering Quality](#dimension-9-prompt-engineering-quality)
    - [Dimension 10: Completeness](#dimension-10-completeness)
  - [4. Generate Comprehensive Evaluation Report](#4-generate-comprehensive-evaluation-report)
  - [5. Deliver Report to User](#5-deliver-report-to-user)
- [Important Guidelines](#important-guidelines)
- [Requirements](#requirements)
- [Context & Standards](#context--standards)

## Instructions

### 1. Find Skill

Identify the skill passed in the directory passed to you or find all in the user's `~/.claude/skills/` directory. For each directory (excluding hidden files), verify it contains a `SKILL.md` file.

Present the user with:
- List of available skills
- Ask which skill to evaluate (or accept skill name as input)

### 2. Read the Skill File

Once a skill is selected, read its `SKILL.md` file and extract:
- Frontmatter metadata (name, description)
- Total line count
- Word count
- Character count
- Structure and sections

#### Error Handling

If SKILL.md is malformed, missing frontmatter, or unreadable:
- Report the specific error to the user (e.g., "SKILL.md missing required frontmatter field: name")
- Skip the full evaluation
- Suggest corrective action if possible

#### Review Example Report Format

Before analyzing, consult the example evaluation reports:
- **`examples/EXAMPLE.md`** - Demonstrates evaluation of a production-ready skill with passing scores
- **`examples/EXAMPLE-WITH-WARNINGS.md`** - Demonstrates evaluation of a near-production skill with warnings and improvement suggestions

These examples show proper report structure, formatting, status indicators (✓ Pass / ⚠ Warning / ❌ Fail), and how to deliver actionable feedback across the quality spectrum.

### 3. Analyze Against Best Practices

Evaluate the skill across **10 dimensions**:

#### Dimension 1: Size & Length
**Guidelines:**
- Body: Under 500 lines (hard maximum)
- Name: Maximum 64 characters
- Description: Maximum 1024 characters (200 char summary preferred)
- Table of Contents: Include if over 100 lines

**Assessment:**
- Count total lines in SKILL.md body
- Flag if over 500 lines
- Compliment if well-sized (ideal: 100-300 lines for medium skills)
- Check if TOC exists (expected for 100+ line skills)

#### Dimension 2: Token Economy
**Guidelines:**
- Default assumption: Claude is already very smart
- Challenge each piece of information: "Does Claude really need this explanation?"
- Avoid over-explaining concepts Claude already knows (e.g., what PDFs are, how libraries work)
- Concise examples preferred over verbose explanations

**Assessment:**
- Are there paragraphs explaining concepts Claude inherently knows?
- Could explanations be shortened without losing meaning?
- Is the skill concise within its size limits, or padded with unnecessary context?
- Does each section justify its token cost?

#### Dimension 3: Degrees of Freedom
**Guidelines:**
- High freedom (text-based instructions): Use when multiple approaches are valid or decisions depend on context
- Medium freedom (pseudocode/scripts with parameters): Use when a preferred pattern exists but variation is acceptable
- Low freedom (specific scripts, few parameters): Use when operations are fragile, consistency is critical, or exact sequence required

**Assessment:**
- Does the skill match instruction specificity to task fragility?
- Are fragile/destructive operations given explicit, low-freedom instructions?
- Are context-dependent tasks given appropriate flexibility?
- Does the skill avoid over-constraining where multiple valid approaches exist?

#### Dimension 4: Scope Definition
**Guidelines:**
- Narrow focus (one skill = one capability)
- Clear boundary of what the skill does and doesn't do
- No scope creep (e.g., "document processing" → "PDF form filling")

**Assessment:**
- Does the description clearly state what the skill does?
- Are there multiple conflicting capabilities within one skill?
- Is the boundary clear to a new user?

#### Dimension 5: Description Quality
**Guidelines:**
- Third-person voice (avoid "I can" or "you can")
- Include both WHAT and WHEN TO USE
- Specific, searchable terminology
- 200 character summary ideal

**Assessment:**
- Voice and tone appropriate?
- Discovery terms clear? (Would users search for these terms?)
- Is "when to use" explained?

#### Dimension 6: Structure & Organization
**Guidelines:**
- Clear section hierarchy (headings, subsections)
- Logical flow (progressive disclosure): start with a small, stable entry point and point to deeper sections/references rather than front-loading everything
- Step-by-step instructions preferred for workflows
- Rules/constraints clearly stated

**Assessment:**
- Is structure logical?
- Can a user easily navigate?
- Are instructions sequential or scattered?

#### Dimension 7: Examples
**Guidelines:**
- Quality over quantity
- Typical: 2-3 examples for basic skills, more for format-heavy
- Concrete (not abstract)
- Show patterns and edge cases

**Assessment:**
- How many examples? (count them)
- Are examples concrete and realistic?
- Do they demonstrate key patterns?
- Are there enough to show variations?

#### Dimension 8: Anti-Pattern Detection
**Red flags (check for these):**
- ❌ Windows-style paths (should use forward slashes)
- ❌ Magic numbers without justification
- ❌ Vague terminology (inconsistent synonyms)
- ❌ Time-sensitive instructions (date-dependent)
- ❌ Nested file references (over 1 level from SKILL.md - all reference files should link directly from SKILL.md)
- ❌ Vague descriptions (missing WHAT or WHEN)
- ❌ Scope creep (trying to do too much)
- ❌ No error handling or validation steps
- ❌ No user feedback loops (for complex workflows)
- ❌ Multiple conflicting approaches for same task
- ❌ MCP tool references without server prefix (should use `ServerName:tool_name` format)
- ❌ Assumed package availability (missing explicit installation instructions)
- ❌ Vague/generic naming (`helper`, `utils`, `tools` instead of imperative verb form like `process-pdfs`)

**Assessment:**
- Count violations
- Severity of each violation
- Impact on usability

#### Dimension 9: Prompt Engineering Quality
**Guidelines:**
- Imperative language (verb-first instructions)
- Explicit rules with clear boundaries
- Validation loops where appropriate (especially for destructive ops)
- Clear error handling
- Assumes user is intelligent (don't over-explain)

**Assessment:**
- Is language imperative?
- Are there validation steps?
- How clear are the rules?
- Is error handling explicit?

#### Dimension 10: Completeness
**Guidelines:**
- Requirements listed (what's needed to use the skill)
- Edge cases acknowledged
- Limitations stated where relevant

**Assessment:**
- Are prerequisites clear?
- Are limitations or edge cases mentioned?
- Is scope of responsibility clear?

### 4. Generate Comprehensive Evaluation Report

Create a detailed evaluation report with these components:

1. **Executive Summary**: 1-2 paragraphs covering