MCP Servers Essential Reference

Skill by ara.so — MCP Skills collection.

This skill provides expertise in selecting, installing, and configuring MCP (Model Context Protocol) servers for AI coding agents like Claude Code, Cursor, Codex, and Gemini CLI. It covers 50 essential servers across 9 categories with installation commands, security best practices, and troubleshooting.

What MCP Servers Are

The Model Context Protocol (MCP) is a standardized interface that allows AI agents to connect to external tools and services. Instead of each AI model implementing custom integrations, MCP provides a "USB-C port for AI" — one protocol that both agents and tools speak.

Key concepts:

• Server: A service that exposes tools/resources via MCP (e.g., GitHub API, database access)
• Transport: How the agent connects (stdio for local, HTTP/SSE for hosted)
• Tool: A function the agent can call (e.g., search_github, run_sql_query)
• Resource: Read-only data the agent can access (e.g., file contents, API docs)

The Three Critical Rules

Before installing any MCP server: