building-mcp-servers

Build MCP servers using the MCP SDK (TypeScript) or FastMCP (Python) to define tools with strict input/output schemas, enabling LLMs to orchestrate external services. The Skill covers scaffolding, tool design, validation, transport configuration (stdio or streamable HTTP), and deployment patterns.

Design tool schemas using Zod (TypeScript) or Pydantic (Python) with strict validation, clear annotations, and standardized naming conventions. Include proper error messages and input/output definitions to ensure LLMs invoke tools correctly and handle responses predictably.

Yes, MCP servers deploy via Docker alongside guidance on transport selection. Choose between stdio (local) and streamable HTTP (remote) transports based on your architecture, plus authentication patterns and security best practices for production environments.

Construct evaluations and quality gates to verify tool correctness, schema compliance, and LLM interaction patterns. The Skill provides guidance on testing frameworks and verification scripts to ensure servers meet functional and technical requirements.

Implement authentication patterns, secure transport configuration, input validation via schemas, and error handling that prevents information leakage. Security best practices cover both local and remote deployments to protect external services from untrusted LLM requests.

This Skill covers building MCP servers from scratch in TypeScript or Python. For consuming or configuring pre-built MCP servers, use the server directly; this Skill focuses on authoring servers with tool design, validation, and deployment.