mcp-builder

id	mcp-builder
name	MCP Builder
description	Guides creation of MCP servers with strong tool design, schemas, and evaluation practices.
category	core
type	core
version	1.0.0
license	MIT
metadata	{"author":"FreakingJSON","source":"OBSOLETE/migration"}
compatibility	["OpenCode","Claude","Gemini","Codex"]

MCP Builder Skill

Build high-quality MCP (Model Context Protocol) servers that expose reliable tools for LLMs.

Instructions

1. Planning

• Balance full API coverage with workflow tools.
• Use descriptive tool names with consistent prefixes (e.g. github_create_issue).
• Keep tool descriptions concise and actionable.
• Design outputs that are focused, paginated, and easy to parse.
• Provide actionable error messages with next steps.

2. Architecture

• Prefer TypeScript with the MCP SDK when possible.
• Use streamable HTTP for remote servers and stdio for local servers.
• Define shared utilities: auth, error handling, pagination, response formatters.

3. Tool Design

• Define input schemas (Zod or Pydantic) with constraints and examples.
• Define output schemas when possible for structured results.
• Include annotations: readOnlyHint, destructiveHint, idempotentHint, openWorldHint.
• Return both text and structured content when supported.

4. Implementation

• Use async I/O and consistent error handling.
• Ensure pagination on list endpoints.
• Keep tools atomic and predictable.

5. Review and Test

• Compile/build the server and run basic checks.
• Test with MCP Inspector or client smoke tests.
• Verify tool discoverability and error paths.

6. Evaluation

• Create 10 realistic, read-only evaluation questions.
• Ensure each question is verifiable and stable.
• Use a simple XML format with qa pairs.

References

• MCP spec sitemap: https://modelcontextprotocol.io/sitemap.xml
• MCP TS SDK: https://raw.githubusercontent.com/modelcontextprotocol/typescript-sdk/main/README.md
• MCP Python SDK: https://raw.githubusercontent.com/modelcontextprotocol/python-sdk/main/README.md

Output Format

• Provide a build plan, tool list, schemas, and testing checklist.

Supported Commands

• "Design an MCP server for: "
• "Draft tool schemas for: "