MCP in 15 minutes

MCP exposes three primitives: tools (operations with side effects), resources (read-only addressable data), and prompts (templated workflows clients can show users). The hard part of MCP isn't the protocol — it's deciding what belongs where.

Rule of thumb: if it has a verb, it's a tool. If it has a noun and a URI, it's a resource. If it's a recipe a user might run, it's a prompt.

Local-only servers ship over stdio. Remote servers ship over HTTPS with auth. Always start local, promote to remote only when you need it.