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 tallclub/matimo --skill skill-creatorgit clone --depth 1 https://github.com/tallclub/matimoWrote 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/tallclub/matimo/skill-creator)<a href="https://agentmods.dev/skills/tallclub/matimo/skill-creator"><img src="https://agentmods.dev/badge/skills/tallclub/matimo/skill-creator/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/tallclub/matimo/skill-creator"><img src="https://agentmods.dev/badge/skills/tallclub/matimo/skill-creator.svg" alt="Reviewed on agentmods" width="80" height="20"></a>- NVIDIA SkillSpector warn
SkillSpector: 1 finding, 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 248 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.
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 | $0.00092 | $0.03228 |
| Opus 5.5 | $0.00037 | $0.01291 |
| Sonnet 5.5 | $0.00018 | $0.00646 |
| Haiku 4.5 | $0.00009 | $0.00323 |
Grade A, and why
skill-creator 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 2mo 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 — 440 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Skill Creator
A skill for creating new skills and iteratively improving them in Matimo.
At a high level, creating a skill goes like this:
- Understand what the skill should do and when it should trigger
- Interview the user to capture requirements and edge cases
- Draft the SKILL.md with proper frontmatter and instructions
- Validate the skill using
matimo_validate_skill - Create the skill using
matimo_create_skill - Iterate based on feedback
When to Use This Skill
- User says "create a skill for X" or "turn this into a skill"
- User wants to capture a workflow as a reusable pattern
- User wants to teach agents how to do a specific task
- User wants to create provider-specific skills for their tools
- User wants to edit, improve, or validate an existing skill
- An agent recognizes a repeatable pattern worth capturing
Step 1: Capture Intent
Start by understanding what the user wants. The current conversation might already contain a workflow to capture (e.g., they say "turn this into a skill"). If so, extract answers from the conversation first — the tools used, the sequence of steps, corrections the user made.
Key questions to answer:
- What should this skill enable an agent to do? Be specific about the outcome.
- When should this skill trigger? What user phrases or contexts should activate it.
- Which Matimo tools does it use? These go in the
apply-tofrontmatter field. - What's the expected workflow? Step-by-step process the agent should follow.
- What are the common errors and edge cases? These become the error handling section.
Step 2: Interview and Research
Proactively ask about:
- Edge cases: What happens when inputs are missing or invalid?
- Error handling: Which errors are common and how to recover?
- Best practices: What patterns produce the best results?
- Anti-patterns: What should agents avoid doing?
- Dependencies: Does this skill require specific tools or providers?
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.
- 2mo ago First seen · 440 lines · 92 tokens per session scan A c1436781b8e4
skill-creator is a skill published in the GitHub repository tallclub/matimo (18 stars, last pushed yesterday), licensed MIT. It adds 92 tokens to every session and 3,228 once invoked, about $0.0004 per session on Opus 5.5. 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.
skill-creator compared with skills from other repositories
| Mod | Type | Stars | Last push | Licence | Scan | Tokens | Works with |
|---|---|---|---|---|---|---|---|
| skill-creatortallclub/matimo | Skill | 18 | yesterday | MIT | A | 92 | Claude Code, Codex |
| imagegenopenai/codex | Skill | 133k | yesterday | Apache-2.0 | A | 113 | Codex |
| playwright-climicrosoft/playwright | Skill | 99k | yesterday | Apache-2.0 | A | 19 | Claude Code |
| local-ai-agentsmicrosoft/ai-agents-for-beginners | Skill | 79k | 4d ago | MIT | A | 200 | Claude Code, Codex |
| systematic-debuggingobra/superpowers | Skill | 313k | 3d ago | MIT | A | 21 | Claude Code |
| next-cache-components-adoptionvercel/next.js | Skill | 143k | today | MIT | A | 95 | Claude Code |
| next-partial-prefetching-adoptionvercel/next.js | Skill | 143k | today | MIT | A | 103 | Claude Code |