Skills Duplicate Detector

Expert skill for identifying duplicate, similar, and overlapping Claude Code skills across your collection using intelligent comparison algorithms.

Purpose

Analyze a collection of Claude Code skills to identify duplicates, near-duplicates, and functionally similar skills. Helps maintain a clean, organized skills collection by detecting redundancy and suggesting consolidation.

When to Use

After bulk downloading skills from multiple sources
Maintaining an existing skills collection
Before committing new skills to a repository
Auditing skill collections for redundancy

Capabilities

1. Duplicate Detection Methods

Exact Name Matching

Identify skills with identical names
Detect name variations with prefixes/suffixes
Find skills differing only in case

Semantic Similarity

Analyze SKILL.md descriptions
Compare stated purposes and capabilities
Identify functional overlap
Calculate similarity scores

Content Analysis

Compare skill file structures
Analyze included scripts and tools
Check for shared dependencies
Detect copy/paste variations

2. Similarity Categories

Perfect Duplicates (100% match)

Identical names and content
Same functionality and purpose
Likely from same source

Near Duplicates (80-99% match)

Similar names with minor variations
Nearly identical functionality
Possible version differences

Functional Overlaps (60-79% match)

Different names, similar purpose
Overlapping capabilities
May serve different use cases

Related Skills (40-59% match)

Adjacent functionality
Complementary features
Worth noting but not duplicates

3. Analysis Outputs

Duplicate Report

# Duplicate Skills Analysis

## Perfect Duplicates (7 found)

### Group 1: Code Review
- **code-review_mrgoonie** (KEEP - most comprehensive)
  - Location: /skills/code-review_mrgoonie
  - Size: 15 KB
  - Features: Requesting, receiving, verification

- **receiving-code-review_obra** (DUPLICATE)
  - Location: /skills/receiving-code-review_obra
  - Similarity: 95%
  - Recommendation: Move to /duplicates

- **requesting-code-review_obra** (DUPLICATE)
  - Location: /skills/requesting-code-review_obra
  - Similarity: 92%
  - Recommendation: Move to /duplicates

**Reason**: All three provide code review functionality. mrgoonie version combines both requesting and receiving in one comprehensive skill.

Usage Instructions

Basic Duplicate Detection

Use the skills-duplicate-detector skill to analyze /skills directory and identify all duplicates.

Detailed Analysis

Use the skills-duplicate-detector skill to:
1. Scan all skills in /skills directory
2. Identify duplicates with 70%+ similarity
3. Generate a detailed report with recommendations
4. Create a DUPLICATES_LOG.md file

Pre-commit Check

Before committing new skills, use skills-duplicate-detector to check if they already exist in the collection.

Detection Algorithm

Phase 1: Name Analysis

# Normalize skill names
def normalize_name(skill_name):
    # Remove source suffixes (_obra, _mrgoonie, etc.)
    # Convert to lowercase
    # Remove special characters
    # Standardize spacing
    return normalized_name

# Find exact and near matches
for skill1, skill2 in pairs:
    name_similarity = levenshtein_distance(
        normalize_name(skill1),
        normalize_name(skill2)
    )

Phase 2: Content Analysis

# Compare SKILL.md descriptions
def compare_descriptions(skill1, skill2):
    # Extract purpose statements
    # Tokenize and compare keywords
    # Calculate semantic similarity
    # Weight by capability overlap
    return similarity_score

Phase 3: Structural Analysis

# Compare file structures
def compare_structure(skill1, skill2):
    # List files and directories
    # Compare organization
    # Check for shared patterns
    # Identify clones vs. variations
    return structure_score

Comparison Heuristics

Name-Based Detection

Exact match: Same name after normalization → 100%
Prefix/suffix variation: skill vs skill_source → 95%
Hyphen/underscore: code-review vs code_review → 90%
Abbreviations: db-helper vs database-helper → 80%

Purpose-Based Detection

Identical purpose: Same goals stated → 95%
Overlapping functionality: 80%+ feature overlap → 85%
Complementary: Different aspects of same domain → 60%
Related: Adjacent problem spaces → 40%

Quality Assessment

When duplicates are found, recommend keeping the version with:

✅ Most comprehensive documentation
✅ Largest feature set
✅ Most recent updates
✅ Better code quality
✅ More complete examples

Output Formats

Console Report

Duplicate Detection Results
===========================

Total skills scanned: 161
Unique skills: 154
Duplicates found: 7
Similarity threshold: 70%

Perfect Duplicates (3 groups):
  - Code review skills (3 items)
  - Debugging skills (2 items)
  - Skill creation tools (3 items)

Near Duplicates (2 groups):
  - Brainstorming skills (2 items)
  - Document skills (2 items)

Recommendations:
  - Move 7 skills to /duplicates
  - Keep 154 unique skills in /skills
  - Estimated disk space saved: 2.3 MB

Markdown Report (DUPLICATES_LOG.md)

Detailed analysis of each duplicate group
Side-by-side comparison tables
Recommendations with reasoning
Links to source repositories

JSON Export

{
  "analysis_date": "2025-11-07",
  "total_skills": 161,
  "unique_skills": 154,
  "duplicates": [
    {
      "group_id": 1,
      "group_name": "code-review",
      "members": [
        {
          "path": "/skills/code-review_mrgoonie",
          "keep": true,
          "reason": "Most comprehensive"
        },
        {
          "path": "/skills/receiving-code-review_obra",
          "keep": false,
          "similarity": 0.95
        }
      ]
    }
  ]
}

Configuration Options

Similarity Thresholds

thresholds:
  perfect_duplicate: 0.95      # 95%+ similarity
  near_duplicate: 0.80         # 80-94% similarity
  functional_overlap: 0.60     # 60-79% similarity
  related: 0.40                # 40-59% similarity
  report_minimum: 0.60         # Only report 60%+ matches

Comparison Weights

weights:
  name_similarity: 0.30        # 30% weight on name matching
  purpose_similarity: 0.40     # 40% weight on purpose/description
  structure_similarity: 0.20   # 20% weight on file structure
  feature_overlap: 0.10        # 10% weight on feature comparison

Output Options

output:
  console_report: true
  markdown_report: true
  json_export: false
  auto_move_duplicates: false  # Require confirmation
  create_backups: true         # Before moving files

Detection Patterns

Common Duplicate Patterns

Source-Suffixed Variants

skill-name_obra
skill-name_mrgoonie
skill-name_diet103

Naming Convention Differences
```
code-review
code_review
codeReview
```

Scope Variations

document-skills         (broad)
scientific-document-skills  (specialized)
pdf-document-skills     (narrow)

Feature Splits

code-review             (combined)
requesting-code-review  (split)
receiving-code-review   (split)

Cómo agregar

Pega en el README de tu repo

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