Skill Showcase
Real-world examples of Skills in production. For those who want to see implementation, not just concepts.
About This Document
After learning concepts in What is Skills and design methods in Creating Skills, this page presents three production Skill implementations. Each demonstrates a different design approach, MCP integration depth, and distribution format, providing a practical reference for Skill design patterns.
Examples Overview
| Skill | Pattern | MCP Integration | Distribution |
|---|---|---|---|
| deepl-glossary-translation | MCP Orchestration | pdf-spec-mcp + DeepL MCP | .claude/skills/ |
| code-review-skill | Checklist-based | None (static knowledge only) | .claude/skills/ / Project Knowledge |
| spec-compliance-skills | Data-driven Validation | None (pre-parsed data) | Cowork Plugin |
deepl-glossary-translation
Repository: shuji-bonji/deepl-glossary-translation
Overview
A Skill that integrates pdf-spec-mcp and DeepL MCP Server to translate the PDF specification (ISO 32000-2) into Japanese with consistent terminology. MCP provides "what can be done" while the Skill defines "how to do it" — an example of combining Skills and MCP among the five layers.
Architecture
Design Highlights
Multi-MCP Orchestration: Chains pdf-spec-mcp (data extraction) → DeepL MCP (translation) → xcomet-mcp (quality evaluation). The Skill itself has no tools — it defines the "usage patterns" for existing MCPs.
5-Step Workflow Definition: Term extraction → Classification → Glossary registration → Translation → Quality verification. Clear steps in Markdown that agents follow autonomously.
External Script Augmentation: Glossary registration requires direct DeepL API calls, so shell scripts are bundled in scripts/. This pattern complements Skill's static knowledge with executable scripts.
Classification
Maps to Pattern 4: MCPs + Skills (Full Integration) in Composition Patterns.
code-review-skill
Repository: shuji-bonji/code-review-skill
Overview
A Skill for conducting code reviews on TypeScript / MCP Server projects. Defines 10-category evaluation criteria and a 3-tier priority framework for consistent review quality.
10-Category Checklist
| Category | Example Checks |
|---|---|
| Bug Detection | Placeholder detection, null checks, async handling |
| User Messages | Language consistency, error actionability |
| Code Suppressions | eslint-disable / @ts-ignore necessity verification |
| Hardcoding | Magic numbers, embedded config values |
| Performance | N+1 problems, cache gaps, sequential async calls |
| Redundancy | Code duplication, unused variables, dead code |
| Type Safety | Eliminate any types, validate external data with Zod |
| Maintainability | Responsibility separation, dependency direction |
| Code Structure | File size >300 lines, function >50 lines, circular dependencies |
| Project-specific | MCP: tool descriptions, Zod .strict() / Angular: component separation |
Priority Framework
| Level | Targets |
|---|---|
| 🔴 High | Runtime bugs, security issues, performance degradation |
| 🟡 Medium | Bug-prone structures, weakened type safety |
| 🟢 Low | Readability improvements, minor refactoring |
Design Highlights
Pure Skill (no MCP required): No external API calls needed. Works by combining with the agent's built-in code analysis capabilities. The simplest form of a Skill.
Split Placement Design: Recommends different detail levels for Claude.ai (Project Knowledge) vs Claude Code (.claude/). A PLACEMENT-GUIDE.md addresses context window constraints.
Classification
A Skills-only pattern among the five layers. It shows that a Skill can work without MCP.
spec-compliance-skills
Repository: shuji-bonji/spec-compliance-skills
Overview
A Cowork Plugin that validates document compliance against W3C/IETF specifications. Ships with pre-parsed normative requirements (MUST/SHOULD/MAY) as embedded data, generating structured validation reports.
Included Skills
epub-quality Validation Flow
Design Highlights
Data-driven Validation: Pre-parses normative requirements from specifications into JSON, bundled within the Skill. Enables validation without real-time MCP server access.
Skill → Plugin Evolution: Functions as a standalone Skill but distributes as a Cowork Plugin (.plugin) for easier installation and updates. An example of Skill distribution evolution.
Incremental Expansion: Released epub-quality first, with pdf-quality and rfc-compliance added progressively. A pattern for bundling multiple Skills in a single Plugin.
Classification
A Skills-only (data-embedded) pattern among the five layers. Instead of real-time data from MCP, it embeds pre-parsed data within the Skill.
Skill Design Space
Skills start with the simple definition of "knowledge written in Markdown," but in practice they encompass diverse design patterns: bundled data files, companion scripts, MCP integration definitions, and Plugin distribution. The key insight is that the essence of a Skill (providing knowledge to agents) remains constant across all patterns.
Related Documentation
- What is Skills - Skills overview
- Skill Design Guide - When and how to design Skills
- How to Create Skills - Step-by-step creation guide
- How to Use Skills - Installation and project integration
- Skill Use Cases - Use case patterns and role separation
- Anti-Patterns Guide - Common failure patterns to avoid
- MCP vs Skills - Essential differences and selection criteria