Creating your own skill

Custom Skills let you package your expertise and procedures so Claude applies them consistently, for you and your team. The format is deliberately simple: files and folders.

Anatomy of a Skill

At minimum, a Skill is a directory with one file:

my-skill/
└─ SKILL.md          # required: instructions + metadata

As it grows, you can bundle more:

weekly-report/
├─ SKILL.md          # the core instructions
├─ references/
│  └─ style-guide.md # loaded only when needed
├─ templates/
│  └─ report.md
└─ scripts/
   └─ format.py      # optional helper code

Claude reads SKILL.md first and pulls in the extra files only when relevant (progressive disclosure).

What goes in SKILL.md

A SKILL.md starts with metadata (a name and a clear description of when to use it), followed by the instructions:

---
name: weekly-report
description: Use when the user asks to create the weekly status report.
  Produces our standard format from raw weekly metrics and highlights.
---

# Weekly Report Skill

## When to use
When the user provides weekly numbers/highlights and asks for "the weekly report".

## Steps
1. Summarize the week in 3 bullets (wins, risks, next focus).
2. Build a metrics table: Metric | This week | Last week | Δ.
3. Write a short "Asks" section if blockers are mentioned.

## Style
- Tone: concise, factual, no hype.
- British English. Lead with outcomes, not activity.

## Output
A single document, ready to paste into email.

The description is everything

Claude decides whether to use a Skill mostly from its description. Make it specific about when the Skill applies, not just what it does.

How to create and use them

• In Claude Code: create the Skill folder in your project; Claude discovers and uses it automatically.
• In claude.ai: add custom Skills via Settings → Features (typically as a zip), on plans with code execution.
• Via the API: upload through the Skills endpoints and reference the Skill by id.

Good Skills to build first

Start with your most repetitive, rule-heavy tasks:

• Your report / summary format
• Your brand voice & writing rules
• A review checklist (e.g. "review this contract for these 8 risks")
• A data-cleaning procedure you run often

Principles for great Skills

• One job per Skill. Keep each focused.
• Write for a new hire. Be explicit; don't assume tribal knowledge.
• Show examples. Include a model of "good" output.
• Iterate. When Claude gets something wrong, update the Skill rather than re-correcting each time.
• Version them. They're just files; track changes like any document.

The Skill Creator

There's a meta-Skill ("Skill Creator") that helps you scaffold new Skills. Ask Claude to help you turn a recurring task into a Skill, and it can draft the SKILL.md for you.

Next: connect Claude to the outside world with MCP & connectors.