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 myths-labs/muse --skill creating-skillsgit clone --depth 1 https://github.com/myths-labs/museWrote 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/myths-labs/muse/creating-skills)<a href="https://agentmods.dev/skills/myths-labs/muse/creating-skills"><img src="https://agentmods.dev/badge/skills/myths-labs/muse/creating-skills/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.
<a href="https://agentmods.dev/skills/myths-labs/muse/creating-skills"><img src="https://agentmods.dev/badge/skills/myths-labs/muse/creating-skills.svg" alt="Reviewed on agentmods" width="80" height="20"></a>- NVIDIA SkillSpector warn
SkillSpector: 6 findings, up to high
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 →
- high Rogue Agent · line 3 Skill modifies its own code, configuration, or behavior at runtime. Self-modification enables an agent to escalate privileges, disable safety constraints, or install persistent backdoors.Fix: Prevent the skill from modifying its own code, SKILL.md, or configuration files. Treat skill files as read-only at runtime.
- high Agent Snooping · line 17 Skill reads from agent configuration directories (.claude/, .codex/, .gemini/). These directories may contain API keys, personal settings, and other credentials that the skill has no legitimate need to access.Fix: Remove all code or instructions that access agent configuration directories (.claude/, .codex/, .gemini/). If configuration values are needed, pass them explicitly as parameters or environment variabl
- 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.
- medium Agent Snooping · line 14 Skill enumerates or reads other installed skills. Access to other skills' SKILL.md files or the skills directory reveals prompt instructions, capabilities, and secrets that should be invisible to peer skills.Fix: Remove all code or instructions that list or read other skills' files or directories. Skills should operate independently; cross-skill access is a privilege escalation.
- medium Rogue Agent · line 162 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.
- medium Excessive Agency · line 306 Skill enables autonomous high-impact decisions without human-in-the-loop verification. Critical operations (destructive commands, financial transactions, data deletion) should require explicit user confirmation.Fix: Add human-in-the-loop confirmation for destructive, irreversible, or high-impact operations. Never auto-execute commands that modify files, send data, or alter system state.
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 | $0.00056 | $0.02004 |
| Opus 5 | $0.00028 | $0.01002 |
| Sonnet 5 | $0.00011 | $0.00401 |
| Haiku 4.5 | $0.00006 | $0.00200 |
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 10d 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.
How it starts
The opening of the file, as written. The whole thing — 314 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>/references
# 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>
<One-line description>
## Quick Start
<Minimal steps to use the skill>
## Core Workflow
<Step-by-step instructions>
## Important Rules
<Critical constraints and requirements>
EOF
# 3. Add helper scripts if value-add
# 4. Add reference files for detailed docs
SKILL.md Structure
Frontmatter (REQUIRED)
---
name: skill-name # lowercase, hyphens, no spaces
description: <desc> # CRITICAL for discovery (max 1024 chars)
---
Advanced Frontmatter (v3.0)
Inspired by Claude Code's internal skills architecture (loadSkillsDir.ts).
---
name: skill-name
description: <What it does>. <Key capabilities>.
# v3.0 fields — separate trigger logic from description
when_to_use: >
Use when user wants to create PR, open pull request,
or merge feature. Also triggers on 'review', 'submit'.
# Security: restrict which tools this skill can use
allowed-tools:
- run_command
- view_file
- grep_search
# Omit dangerous tools like write_to_file for read-only skills
# Auto-activate when editing files matching these paths
paths:
- src/auth/**
- lib/security/**
# Parameterized skills: $1, $2 substitution
arguments: [target_file, test_scope]
argument-hint: "<file> [scope]"
# Control execution depth
effort: thorough # Options: minimal, standard, thorough
# Specify a model for this skill (rare)
# model: claude-sonnet-4-20250514
# Whether users can invoke directly (vs agent-only)
user-invocable: true
# Pure text skill (no LLM invocation)
# disable-model-invocation: false
# Isolated execution context
# context: fork
---
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.
- 10d ago First seen · 314 lines · 56 tokens per session scan A 2086fd39bb1c
creating-skills is a skill published in the GitHub repository myths-labs/muse (32 stars, last pushed 4d ago), licensed MIT. It adds 56 tokens to every session and 2,004 once invoked, about $0.0003 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 2026-08-30.
Other skills, from other repositories
context-receipts
Emit privacy-safe receipts for context selection, deferral, hydration, compaction, pruning, delegation, usage attribution, and boundary handoffs.
evidence-attestation
Emit privacy-safe evidence attestations for agent actions, reviews, memory answers, handoffs, scores, approvals, and tool dispatches.
skill-policy-receipts
Use when a task must obey a hard project policy, such as "do not generate tests for internal services", "do not call production APIs", or "do not edit generated files". Emits a privacy-safe receipt before writes and after guard checks.
requirements-authoring
To author, update, and validate functional/non-functional requirements as atomic units with user approval.
ijfw-workflow
Use when the user says: 'build', 'create', 'plan', 'new project', 'brainstorm', 'design', 'UI', 'website', 'dashboard', 'app', 'help me build', 'launch', 'book', 'campaign', or anything project-level. Skill body decides Quick vs Deep path.
ijfw-plan
Use when the user says 'plan this', 'plan it', 'make a plan', 'let's plan', 'draft a plan', 'how should we tackle this', 'break this down', or invokes '/ijfw-plan'. Produces a falsifiable PLAN.md (software, book, campaign, design, research) with task breakdown, dependency wave-table, and success criteria — gated by…