mcp-builder

Build an MCP server by designing tool-based APIs that expose external services to LLMs. Use FastMCP for Python or MCP SDK for Node/TypeScript, define input validation with Pydantic or Zod, annotate tools clearly, and choose a transport layer—stdio, SSE, or HTTP—based on your deployment needs.

Design tools with context-aware outputs: enforce concise response formats, set character limits, prioritize high-signal JSON or Markdown results, and include pagination metadata to manage token budgets. Tailor tool outputs to the task scope so LLMs stay focused and efficient.

Yes. MCP servers work across Python using FastMCP and Node/TypeScript using MCP SDK. Both support the same core patterns—tool annotations, input validation, output formatting, and transport options—so you can choose based on your environment and workflow needs.

Address pagination by including metadata in responses and limiting result sets; implement input validation to prevent malformed requests; add error handling for external API failures; and enforce security through authenticated transports. These non-functional requirements ensure robust, production-ready MCP servers.

Evaluate whether your MCP server meets functional requirements—tools match workflows, responses fit context budgets—and non-functional ones: input validation passes edge cases, error handling recovers gracefully, pagination scales, and transport security is enforced. Test with real LLM interactions before deployment.