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 agentmods add skills/rhtevan/agentfs/skill-gennpx skills add rhtevan/agentfs --skill skill-gengit clone --depth 1 https://github.com/rhtevan/agentfsWrote 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/rhtevan/agentfs/skill-gen)<a href="https://agentmods.dev/skills/rhtevan/agentfs/skill-gen"><img src="https://agentmods.dev/badge/skills/rhtevan/agentfs/skill-gen.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 | $0.00024 | $0.05968 |
| Opus 5 | $0.00012 | $0.02984 |
| Sonnet 5 | $0.00005 | $0.01194 |
| Haiku 4.5 | $0.00002 | $0.00597 |
Grade B, and why
skill-gen scanned grade B with 1 finding 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 3d 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.
Instruction-override phrasingmediumPrompt injection
Text telling the model to disregard its earlier instructions or safety rules is the shape of a prompt injection, whoever wrote it.
(hidden instructions, role overrides, "ignore previous instructions") Downgraded: this mod is about security review, or the phrase is quoted, so it is likely naming the pattern rather than instructing it.
How it starts
The opening of the file, as written. The whole thing — 614 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Skill Gen
Scope guard: This skill is not available in LITE scope projects. LITE scope does not support skills or knowledge bundles. If the target project's AGENTS.md contains
agentfs-scope: lite, refuse with a clear message.
Create new skills, modify and improve existing ones with built-in AgentFS conventions. Operates in three modes: simple (quick scaffold), advanced (full eval/iterate/optimize loop using upstream Anthropic skill-creator), and skill check (audit existing skills against five quality principles). Default mode is simple; use advanced when requesting "thorough", "with evals", or "production quality".
This is a proxy skill that operates in three modes:
| Mode | When | What Happens |
|---|---|---|
| Simple (default) | Quick utility skills, SOPs, small workflows | Scaffold + write + AgentFS post-creation checklist |
| Advanced | "advanced", "thorough", "with evals", "production quality" | Full upstream eval/iterate/optimize loop + AgentFS checklist |
| Skill Check | "check skill", "skill check", "audit skill" | Audit existing skill against five quality principles |
Mode Selection
Detect mode from user's language:
- Simple (default): "create a skill", "make this reusable", "turn this into a skill", "skill for this workflow"
- Advanced: "create a skill, advanced", "thorough skill", "production quality skill", "with evals", "benchmark this skill"
- Skill Check: "skill check", "scan skill", "check skill", "audit skill", "skill scan", "verify skill quality"
When in doubt, ask: "Do you want a quick skill scaffold, or a thorough process with test cases and evaluation?"
Skill Design Principles
Before creating any skill, understand the three foundational principles that govern skill architecture. These apply to both Simple and Advanced modes.
Non-Interactive Scripts
Scripts under scripts/ MUST be non-interactive — they MUST NOT use
read, select, interactive prompts, or any mechanism that blocks
waiting for stdin. All inputs MUST be accepted via CLI arguments,
environment variables, or input files.
What ships with it
4 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.
- 3d ago First seen · 614 lines · 24 tokens per session scan B d092f00973e2
skill-gen is a skill published in the GitHub repository rhtevan/agentfs (2 stars, last pushed 4d ago), licensed Apache-2.0. It adds 24 tokens to every session and 5,968 once invoked, about $0.0001 per session on Opus 5. A static security scan graded it B with 1 finding (instruction-override phrasing). No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-31.
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