write-a-skill

write-a-skill is a skill for Claude Code from gyuch-an02/claude-omakase. It costs 35 tokens per session (396 once invoked), scanned A, original, MIT.

A guide for creating reusable Claude Code skills, which are instruction files that automate recurring development workflows.

In plain words
What is it for?
Use it to define a skill's purpose and triggers, write its SKILL.md file, test it, and refine it.
Why use it?
It turns repeated instructions into a documented workflow that can be triggered in future coding sessions.

Skill for Claude Code

Written for Claude Code: shipped in a Claude Code plugin. Also seen: reads .claude/ paths; mentions Claude Code.

Part of the claude-omakase plugin — 8 skills, 3 hooks, 1 MCP server shipped together

Good fit Use it to define a skill's purpose and triggers, write its SKILL.md file, test it, and refine it.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/gyuch-an02/claude-omakase/write-a-skill
Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

Any agent
npx skills add gyuch-an02/claude-omakase --skill write-a-skill
Clone the repo
git clone --depth 1 https://github.com/gyuch-an02/claude-omakase

Made for: Claude Code.

Or install claude-omakase, the plugin that ships this one along with the rest of its 8 skills, 3 hooks, 1 MCP server.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

agentmods badge for write-a-skill

README.md
[![agentmods](https://agentmods.dev/badge/skills/gyuch-an02/claude-omakase/write-a-skill/github.svg)](https://agentmods.dev/skills/gyuch-an02/claude-omakase/write-a-skill)
Your own site
<a href="https://agentmods.dev/skills/gyuch-an02/claude-omakase/write-a-skill"><img src="https://agentmods.dev/badge/skills/gyuch-an02/claude-omakase/write-a-skill/github.svg" alt="Measured on agentmods" height="20"></a>

Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

agentmods 80×15 button for write-a-skill

Your own site · 80×15
<a href="https://agentmods.dev/skills/gyuch-an02/claude-omakase/write-a-skill"><img src="https://agentmods.dev/badge/skills/gyuch-an02/claude-omakase/write-a-skill.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 35 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 396 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe. Third-party audits
  • NVIDIA SkillSpector warn 7 Sept 2026
SkillSpector: 1 finding, up to medium

These are SkillSpector’s own severities. On a checked sample its high-severity flags on skills were ~96% false positives — a documented command, a public API, a “never do X” rule — so we show them as a caution to read, not a verdict. Why →

  • medium Rogue Agent · line 3
    Skill establishes unauthorized persistence across sessions via cron jobs, startup scripts, or state files. Session persistence allows an attacker to maintain access beyond the current interaction.
    Fix: Remove any persistence mechanisms (cron jobs, startup scripts, state files). Skills should not maintain state across sessions without explicit user consent.
How audits are shown
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5.1 $0.00035 $0.00396
Opus 5 $0.00017 $0.00198
Sonnet 5 $0.00007 $0.00079
Haiku 4.5 $0.00003 $0.00040

Measured 11d ago against content hash 4723f3e8d087, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-10, from the pricing page.

Security

Grade A, and why

write-a-skill scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 11d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

skills/write-a-skill/SKILL.md · 50 lines

What it actually says

Write a Skill

Help the user turn a recurring workflow into a reusable Claude Code skill.

Process

  1. Understand the workflow: ask what task the user repeats. What triggers it? What does success look like?
  2. Draft a SKILL.md:
    • YAML frontmatter: name, description, triggers (3-5 phrases that activate it)
    • Body: concise instructions Claude follows when the skill activates
    • Include steps, examples, and what NOT to do
  3. Write the file: create ~/.claude/skills/<name>/SKILL.md with the draft
  4. Test it: ask the user to start a new session and trigger the skill by saying one of the trigger phrases
  5. Iterate: refine based on what felt off in the test

Good skill anatomy

---
name: my-skill
description: One sentence. When to use it.
triggers: ["phrase 1", "phrase 2", "phrase 3"]
---

# My Skill

What Claude does when this skill activates. Be concrete.

## Steps
1. ...
2. ...

## Examples
**User:** [trigger phrase]
**Claude:** [response]

Tips

  • Keep it under 200 lines — skills should be focused
  • Triggers should be natural phrases the user actually says
  • One skill = one workflow. Don't bundle unrelated things.
  • If the skill needs reference data (e.g. API docs), add a separate file and reference it
Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 11d ago First seen · 50 lines · 35 tokens per session scan A 4723f3e8d087

Subscribe to this mod's changes

write-a-skill is a skill published in the GitHub repository gyuch-an02/claude-omakase (8 stars, last pushed today), licensed MIT. It adds 35 tokens to every session and 396 once invoked, about $0.0002 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-31.