mcp-tool-dev SKILL.md skillA
mcp-tool-dev from andisab/swe-marketplace is an agent skill: a SKILL.md folder an AI agent loads when a task calls for it.
mdr add andisab/swe-marketplace/mcp-tool-dev@git:20260327.71db556Pins git:20260327.71db556 in mdr.lock. Pin the fingerprint instead.
- Audit grade
- A, 17 of 17 checks passed
- Kind
- SKILL.md skill
- Repository
- andisab/swe-marketplace
- Path
plugins/context-engineering/skills/mcp-tool-dev/SKILL.md- Versions recorded
- 1
- Latest version
- git:20260327.71db556, committed Mar 27, 2026
- Size
- 6,828 bytes
- Repository stars
- 21
- License
- MIT
Create MCP tools — individual tool functions exposed via Model Context Protocol. Use this skill whenever users mention MCP tools, tool handlers, tool functions, tool definitions, or want to add capabilities to an MCP server. Also use when the conversation involves designing tool schemas, writing tool descriptions, or implementing tool input validation. Covers FastMCP patterns, Anthropic tool description best practices, and testing strategies. Activate for: - "Create an MCP tool" -…
Collected from public GitHub. Every version is saved exactly as it was and never changes. Install it at an exact version with the mdr tool, and every file is checked before it reaches your agent. The main file is checked against the SHA-256 fingerprint recorded here, and the others against the fingerprints GitHub keeps for its source commit. The automatic checks below grade the latest version, and the same checks always give the same file the same grade.
What the file says
# MCP Tool Creation Create individual MCP tool functions that follow Anthropic's tool design best practices and the Model Context Protocol specification. ## What MCP Tools Are An MCP tool is a single function exposed via the Model Context Protocol that an LLM can invoke. Each tool has: - **Name**: Verb-noun format (`search_documents`, `get_user`, `create_issue`) - **Description**: 3-4 sentences explaining what the tool does, when to use it, and when not to - **Input schema**: JSON Schema defining parameters with clear descriptions - **Handler**: Async function that processes the input and returns MCP content blocks Tools can be standalone (single-file utilities) or part of an MCP server (grouped related tools). ## When to Use This Skill - Creating a single tool function for an existing or new MCP server - Designing tool schemas and descriptions - Implementing tool input validation and error handling - Adding capabilities to a FastMCP server ## When NOT to Use - Building a complete multi-tool MCP server from scratch — use `mcp-server-dev` instead - Creating Claude Code agents, skills, or commands — use their respective creation skills ## Tool Anatomy …
Read the whole file at its exact version.
How to install
mdr add andisab/swe-marketplace/mcp-tool-dev@sha256:5e5fd32b4a5667e6The line at the top of this page pins the label git:20260327.71db556, which is what most people want. This one pins the sha256 fingerprint of the contents instead, so it survives a label being moved. Either way the exact version is written to mdr.lock, and mdr install downloads and checks those contents again, so it installs them exactly or stops with an error.
[](https://markdownregistry.com/a/art_vg5lrjdxlctrzbgc)
2 badge image fetches in 30 days. What the badge shows.
Versions
The registry has recorded 1 version of this file, committed on Mar 27, 2026.
Audit of the latest version
- pass: Frontmatter block present
- pass: Frontmatter declares a name
- pass: Frontmatter declares a description
- pass: Size between 200 bytes and 200 KB (6828 bytes)
- pass: No zero-width or bidi control characters
- pass: No instruction hidden inside an HTML comment
- pass: No link to an exfiltration or paste host
- pass: No credential-shaped string
- pass: No instruction to send local credentials anywhere
- pass: No text hidden with inline styles
- pass: No prompt-injection phrasing
- pass: No curl or wget piped into a shell
- pass: No recursive delete of root, home or parent
- pass: No instruction to read or print local credentials
- pass: No base64 blob over 200 characters
- pass: No link to a raw IP address
- pass: No script tag
Source
andisab/swe-marketplace · 21 stars · license MIT · pushed 2026-10-17 · branch main
API
GET https://markdownregistry.com/api/v1/artifacts/art_vg5lrjdxlctrzbgc GET https://markdownregistry.com/api/v1/resolve?ref=andisab/swe-marketplace/mcp-tool-dev GET https://markdownregistry.com/api/v1/blob/5e5fd32b4a5667e629793c30f20b03804113ac9985c3141ddd9f10679a8ecf54
Your AI assistant does the legwork. You hear about the deals worth your word. Hand yours the standing instructions at modelranch.com and it joins the network that reads files like this one.
Guides: the SKILL.md format and its required fields · what to check before you install a skill · how to pin a skill to an exact version · where to find agent skills · keeping a team on the same skills · which agent file does what.