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 dog-qiuqiu/invincat --skill skill-creatorgit clone --depth 1 https://github.com/dog-qiuqiu/invincatWrote 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/dog-qiuqiu/invincat/skill-creator)<a href="https://agentmods.dev/skills/dog-qiuqiu/invincat/skill-creator"><img src="https://agentmods.dev/badge/skills/dog-qiuqiu/invincat/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/dog-qiuqiu/invincat/skill-creator"><img src="https://agentmods.dev/badge/skills/dog-qiuqiu/invincat/skill-creator.svg" alt="Reviewed on agentmods" width="80" 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 | $0.00159 | $0.04149 |
| Opus 5 | $0.00079 | $0.02074 |
| Sonnet 5 | $0.00032 | $0.00830 |
| Haiku 4.5 | $0.00016 | $0.00415 |
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 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.
This is a copy
86% identical to skill-creator — 141 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 — 384 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Skill Creator
Skill Location for Invincat
Invincat CLI loads skills from five sources, listed here from lowest to highest precedence:
| # | Directory | Scope | Notes |
|---|---|---|---|
| 0 | <package>/built_in_skills/ |
Built-in | Ships with Invincat CLI |
| 1 | ~/.invincat/<agent>/skills/ |
User (deepagents alias) | Default for invincat-cli skills create |
| 2 | ~/.agents/skills/ |
User | Shared across agent tools |
| 3 | .invincat/skills/ |
Project (deepagents alias) | Default for invincat-cli skills create --project |
| 4 | .agents/skills/ |
Project | Shared across agent tools |
<agent> is the agent configuration name (default: agent). When two directories contain a skill with the same name, the higher-precedence version wins — project skills override user skills, and any user or project skill overrides built-in skills.
Example directory layout:
~/.invincat/agent/skills/ # user skills (lowest precedence)
├── skill-name-1/
│ └── SKILL.md
└── ...
<project-root>/.invincat/skills/ # project skills (higher precedence)
├── skill-name-2/
│ └── SKILL.md
└── ...
Core Principles
Concise is Key
The context window is a public good. Skills share the context window with everything else the agent needs: system prompt, conversation history, other Skills' metadata, and the actual user request.
Default assumption: The agent is already very capable. Only add context the agent doesn't already have. Challenge each piece of information: "Does the agent really need this explanation?" and "Does this paragraph justify its token cost?"
Prefer concise examples over verbose explanations.
Set Appropriate Degrees of Freedom
Match the level of specificity to the task's fragility and variability:
High freedom (text-based instructions): Use when multiple approaches are valid, decisions depend on context, or heuristics guide the approach.
Medium freedom (pseudocode or scripts with parameters): Use when a preferred pattern exists, some variation is acceptable, or configuration affects behavior.
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.
- 11d ago First seen · 384 lines · 159 tokens per session scan A b1613e0ba94a
skill-creator is a skill published in the GitHub repository dog-qiuqiu/invincat (155 stars, last pushed 3mo ago), licensed MIT. It adds 159 tokens to every session and 4,149 once invoked, about $0.0008 per session on Opus 5. A static security scan graded it A with 0 findings. It is 86% identical to skill-creator, differing in 141 lines, and is treated as a copy.
Other skills, from other repositories
skillpack-creator
Create a reusable SkillPack from a successful completed task. Use when the user wants to convert a one-off research, coding, analysis, or content workflow into a distributable local SkillPack with skillpack.json, local skills under skills/, starter prompts, start scripts, and an optional zip package.
skill-creator
Create new skills, modify and improve existing skills, and measure skill performance. Use when users want to create a skill from scratch, edit, or optimize an existing skill, run evals to test a skill, benchmark skill performance with variance analysis, or optimize a skill's description for better triggering accuracy.
todos
This chat has a shared, live TODO plan — your tasks for the conversation, which the user also edits. Read this skill and reach for the todo tools whenever a request takes more than a couple of steps. It covers the plan model (group = task, items = its steps; loose items are the user's lane), how to work it: propose…
writing-workflow-skills
Use when adding a new workflow skill to pi-thinkrail-workflow, changing an existing workflow skill's role, trigger, handoff, or structure, or checking a workflow skill against the workflow system's rules. Not for authoring general-purpose skills outside this package.
reviewing-changes
Use when a review package asks you to review a plan step's change set (todo.startReview): you are the REVIEWER, not the author. How to judge an agent-written diff, file findings with addreviewcomment, and settle with exactly one reviewverdict.
asking-user-questions
Use when composing an askuserquestion round inside a workflow, or when a workflow skill names it at a question step. Shared norms for the tool — not a workflow, nothing to execute.