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.
npx skills add fvadicamo/dev-agent-skills --skill creating-skillsgit clone --depth 1 https://github.com/fvadicamo/dev-agent-skillsWrote 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.
[](https://agentmods.dev/skills/fvadicamo/dev-agent-skills/creating-skills)<a href="https://agentmods.dev/skills/fvadicamo/dev-agent-skills/creating-skills"><img src="https://agentmods.dev/badge/skills/fvadicamo/dev-agent-skills/creating-skills.svg" alt="Measured on agentmods" height="20"></a>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.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5.1 | $0.00070 | $0.01403 |
| Opus 5 | $0.00035 | $0.00701 |
| Sonnet 5 | $0.00014 | $0.00281 |
| Haiku 4.5 | $0.00007 | $0.00140 |
Grade A, and why
creating-skills 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 8d 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.
This is a copy
86% identical to creating-skills — 117 lines differ, which has more behind it and is treated as the original. This page carries a canonical link to it rather than competing with it.
How it starts
The opening of the file, as written. The whole thing — 159 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Creating skills
Guide for creating Claude Code skills following Anthropic's official best practices.
Quick start
# 1. Create skill directory
mkdir -p ~/.claude/skills/<skill-name>
# 2. Create SKILL.md with frontmatter
cat > ~/.claude/skills/<skill-name>/SKILL.md << 'EOF'
---
name: <skill-name>
description: <What it does>. Use when <trigger phrases>. <Key capabilities>.
---
# <Skill title>
<Instructions for the skill workflow>
EOF
# 3. Add optional resources as needed
mkdir -p ~/.claude/skills/<skill-name>/{scripts,references,assets}
SKILL.md structure
Frontmatter (YAML between --- markers)
| Field | Required | Description |
|---|---|---|
name |
No | Display name. Defaults to directory name. Lowercase, hyphens, max 64 chars. |
description |
Recommended | What + when + capabilities. Max 1024 chars. Determines when Claude activates the skill. |
allowed-tools |
No | Tools Claude can use without asking permission when skill is active. |
argument-hint |
No | Autocomplete hint for arguments. Example: [issue-number] |
disable-model-invocation |
No | true to prevent auto-invocation (manual /name only). |
user-invocable |
No | false to hide from / menu (background knowledge only). |
model |
No | Model override when skill is active. |
context |
No | fork to run in isolated subagent context. |
agent |
No | Subagent type when context: fork. Built-in: Explore, Plan, general-purpose. |
hooks |
No | Lifecycle hooks scoped to this skill. |
Invocation control matrix
| Configuration | User can invoke | Claude can invoke |
|---|---|---|
| (defaults) | Yes | Yes |
disable-model-invocation: true |
Yes | No |
user-invocable: false |
No | Yes |
Description formula
<What it does>. Use when <trigger phrases>. <Key capabilities>.
Include action verbs ("create", "handle"), user intent ("wants to", "needs to"), and domain keywords users would say.
What ships with it
2 files beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.
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.
- 8d ago First seen · 159 lines · 70 tokens per session scan A ba4f7f6dc8cb
creating-skills is a skill published in the GitHub repository fvadicamo/dev-agent-skills (72 stars, last pushed 2d ago), licensed MIT. It adds 70 tokens to every session and 1,403 once invoked, about $0.0003 per session on Opus 5. A static security scan graded it A with 0 findings. It is 86% identical to creating-skills, differing in 117 lines, and is treated as a copy.
Other skills, from other repositories
bulwark-brainstorm
Role-based brainstorming with dual modes: --scoped (sequential Task tool, 5 roles) and --exploratory (Agent Teams peer debate, 4 roles). Use for feasibility assessment and idea validation.
plan-creation
Create structured implementation plans via a 4-role scrum team (Product Owner, Architect, Eng/Delivery Lead, QA/Critic) with optional Agent Teams peer debate mode.
anthropic-validator
Validates Claude Code assets (skills, hooks, agents, commands, MCP servers, plugins) against official Anthropic standards. Fetches latest docs dynamically and produces structured validation reports.
code-review
Comprehensive code review with distinct aspect based sections. Use when reviewing code, checking for security issues, finding type safety problems, auditing code quality, or when user asks to review code, PRs or changes. Three-phase workflow runs static tools, LLM judgment, and writes diagnostic log.
create-subagent
Generates single-purpose Claude Code sub-agents for use via the Task tool. Use when creating dedicated sub-agents, scaffolding agent definitions, or generating agents with diagnostics and permissions setup.
test-audit
Audit test suites for T1-T4 violations using AST analysis, mock detection, and multi-stage synthesis. Invoke when user asks to audit tests, check test quality, find mock violations, review test effectiveness, or inspect test suites for over-mocking. Triggers automatic rewrites when quality gates fail.