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 wyattowalsh/agents --skill mcp-creatorgit clone --depth 1 https://github.com/wyattowalsh/agentsWrote 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/wyattowalsh/agents/mcp-creator)<a href="https://agentmods.dev/skills/wyattowalsh/agents/mcp-creator"><img src="https://agentmods.dev/badge/skills/wyattowalsh/agents/mcp-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/wyattowalsh/agents/mcp-creator"><img src="https://agentmods.dev/badge/skills/wyattowalsh/agents/mcp-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 | $0.00050 | $0.04893 |
| Opus 5.5 | $0.00020 | $0.01957 |
| Sonnet 5.5 | $0.00010 | $0.00979 |
| Haiku 4.5 | $0.00005 | $0.00489 |
Grade A, and why
mcp-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 1mo 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 — 514 lines — stays where its author put it; the contents beside it link to each section on GitHub.
MCP Creator — FastMCP v3
Build production-ready MCP servers with FastMCP v3 (3.0.0rc2). This skill guides through research, scaffolding, implementation, testing, and deployment. All first-party output follows this repo's conventions: mcp/<name>/ directory, fastmcp.json config, exact uv workspace member, imperative voice, kebab-case naming. Reserve mcp/servers/ for machine-local third-party MCP installs; it is gitignored.
Target: FastMCP v3 rc2 — Provider/Transform architecture, 14 built-in middleware, OAuth 2.1, server composition, component versioning, structured output, background tasks, elicitation, sampling.
Input: $ARGUMENTS — the service, API, or capability to wrap as an MCP server.
Dispatch
Route $ARGUMENTS to the appropriate mode:
| $ARGUMENTS pattern | Mode | Start at |
|---|---|---|
| Service/API name (e.g., "GitHub", "Stripe") | New server | Phase 1 |
Path to existing first-party server (e.g., mcp/myserver/) |
Extend | Phase 3 |
| OpenAPI spec URL or file path | Convert OpenAPI | Phase 2 (scaffold) then load references/server-composition.md §6 |
| FastAPI app to convert | Convert FastAPI | Phase 2 (scaffold) then load references/server-composition.md §7 |
| Error message or "debug" + description | Debug | Load references/common-errors.md, match symptom |
| "learn" or conceptual question | Learn | Load relevant reference file, explain |
| Empty | Gallery / help overview | Show available modes and example invocations |
Consult Live Documentation
Before implementation, fetch current FastMCP v3 docs. Bundled references capture rc2 — live docs may be newer.
- Context7 —
resolve-library-idfor "fastmcp", thenquery-docsfor the topic. - WebFetch —
https://gofastmcp.com/llms-full.txt— comprehensive LLM-optimized docs. - WebSearch fallback —
site:gofastmcp.com <topic>for specific topics.
If live docs contradict bundled references, live docs win. Always fetch live docs first — API details shift between rc2 and stable.
What ships with it
24 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.
- evals/evals.json 4.0 KB
- evals/server-scaffolding.json 992 B
- evals/tool-definition.json 817 B
- references/auth-and-security.md 23 KB
- references/common-errors.md 21 KB
- references/deployment.md 11 KB
- references/fastmcp-v3-api.md 33 KB
- references/quick-reference.md 2.4 KB
- references/resources-and-prompts.md 5.6 KB
- references/server-composition.md 18 KB
- references/testing.md 21 KB
- references/tool-design.md 37 KB
- scripts/asset_toolkit/__init__.py 303 B runs code
- scripts/asset_toolkit/_shared.py 5.6 KB runs code
- scripts/asset_toolkit/common.py 3.0 KB runs code
- scripts/asset_toolkit/package.py 43 KB runs code
- scripts/asset_toolkit/validate_evals.py 11 KB runs code
- scripts/asset_toolkit/validate_hooks.py 13 KB runs code
- scripts/asset_toolkit/validate_skill.py 3.6 KB runs code
- scripts/check.py 1.5 KB runs code
- scripts/scaffold_mcp.py 4.7 KB runs code
- templates/fastmcp.json 137 B
- templates/pyproject.toml 371 B
- templates/server.py 887 B runs code
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.
- 1mo ago First seen · 514 lines · 50 tokens per session scan A 92c857c11afb
mcp-creator is a skill published in the GitHub repository wyattowalsh/agents (5 stars, last pushed 1mo ago), licensed MIT. It adds 50 tokens to every session and 4,893 once invoked, about $0.0002 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 2026-09-03.
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