claude-code-slides

Skills — Setup & Usage Guide

Related slides: Slide 10 — On-Demand Expertise, Slide 11 — Curate, Don’t Hoard, Slide 12 — Use Skill to Create Skill

Official docs: Claude Code Skills

What Are Skills?

Skills are folders of instructions, scripts, and resources that Claude Code loads dynamically when relevant. They inject workflow and process — not just knowledge.

my-skill/
├── SKILL.md           # Main instructions (required)
├── references/        # Deep knowledge, loaded when needed
├── templates/         # Templates to fill in
└── scripts/           # Executable scripts

Skills use progressive disclosure: metadata loads first (~100 tokens), full instructions only when matched. Minimal context cost.

Installing Skills

Method 1: Install from Marketplaces

Marketplaces are curated collections of plugins/skills. Install with:

claude plugin install --marketplace <marketplace-name> <plugin-name>

Official Marketplaces

Marketplace Description Example
claude-plugins-official Anthropic’s official plugins superpowers, hookify, pr-review-toolkit
anthropic-agent-skills Anthropic’s agent skills document-skills (pdf, docx, pptx, xlsx, etc.) 
# Install Superpowers (structured delegation framework)
claude plugin install --marketplace claude-plugins-official superpowers

# Install document skills (pdf, docx, spreadsheets, etc.)
claude plugin install --marketplace anthropic-agent-skills document-skills

Community Marketplaces

Marketplace Description Link
obsidian-skills Obsidian vault management github.com/kepano/obsidian-skills
claude-drawio Draw.io diagram creation github.com/tuandinh0801/claude-drawio
claude-hud Status line dashboard github.com/jarrodwatts/claude-hud
sap-aicore-cli SAP AI Core CLI integration Internal 
# Install Draw.io plugin
claude plugin install --marketplace claude-drawio drawio-plugin

# Install Playwright skill
claude plugin install --marketplace playwright-skill playwright-skill

Method 2: Install Individual Skills via skills.sh

skills.sh by Vercel is a directory of individual skills you can install with a single command.

npx skills add <owner/repo> --skill <skill-name>

Security tip: Always check the Security tab on skills.sh before installing. It shows an audit of what the skill can access and execute.

Finding Skills

Use the find-skills skill to search for existing public skills:

npx skills add https://github.com/vercel-labs/skills --skill find-skills

Once installed, ask Claude Code to find skills for any topic:

> Find skills for testing React components

Example Installations

# Vercel React best practices
npx skills add vercel-labs/skills --skill vercel-react-best-practices

# Web design guidelines
npx skills add vercel-labs/skills --skill web-design-guidelines

Creating Your Own Skills

Use the skill-creator skill

The skill-creator skill from anthropic-agent-skills is purpose-built for creating new skills following best practices.

# Make sure document-skills is installed (includes skill-creator)
claude plugin install --marketplace anthropic-agent-skills document-skills

Then in Claude Code:

> /skill-creator Create a skill that analyzes promptfoo evaluation
  results and helps construct new test cases

The skill-creator will:

  1. Ask clarifying questions about your workflow
  2. Scaffold the folder structure (SKILL.md, references/, scripts/)
  3. Write the skill following progressive disclosure best practices
  4. Test that the skill activates correctly

Example: promptfoo Skill (Personal Workflow)

This is a custom skill I created for analyzing LLM evaluation results and constructing test cases.

What it does:

Structure:

promptfoo/
├── SKILL.md                        # Workflow: setup → write → run → analyze
├── references/
│   └── report-template.md          # Template for analysis reports
└── scripts/
    └── analyze_eval.py             # Python script for parsing results

Key design decisions:

Skills I Recommend

Development Workflow

Skill Source What it does
superpowers claude-plugins-official Structured delegation: brainstorm → plan → execute → review
pr-review-toolkit claude-plugins-official Multi-agent PR review (code, tests, types, silent failures)
hookify claude-plugins-official Create hooks from conversation patterns

Document & Content

Skill Source What it does
document-skills anthropic-agent-skills PDF, DOCX, XLSX, PPTX, canvas design, frontend design, MCP builder, skill-creator

Browser & Testing

Skill Source What it does
agent-browser Custom (.agents/skills/) CLI-based browser automation — no MCP needed
promptfoo Custom (.claude/skills/) LLM eval analysis and test case construction

Productivity

Skill Source What it does
nlm-skill Custom (.claude/skills/) NotebookLM CLI integration
obsidian obsidian-skills marketplace Obsidian vault management
claude-hud claude-hud marketplace Status line / dashboard
drawio-plugin claude-drawio marketplace Draw.io diagram creation — shameless plug, if you find it useful give it a star!

Tips

  1. Curate, don’t hoard — 20-30 targeted skills beat 200+ generic ones. Too many skills dilute activation accuracy.
  2. Prefer CLI skills over MCP — CLI tools are more secure, more efficient, and don’t consume context when idle.
  3. Use progressive disclosure — SKILL.md should be a summary. Put heavy knowledge in references/, executable logic in scripts/.
  4. Check security before installing — Review the Security tab on skills.sh. Review marketplace source code.
  5. Use skill-creator — Don’t handwrite skills from scratch. The skill-creator follows best practices by default.

Further Reading