"CLI is enough."
"Skills make MCP unnecessary."
Not quite.
We're heading into a world where AI agents connect to hundreds of outside services.
MCP shifts that cost to the server side - build once, connect many.
3 ways agents use tools
| CLI | Skill | MCP | |
|---|---|---|---|
| What | Program | Playbook | Protocol |
| Setup | Install + configure | Download or Write | Add + Connect |
| API Doc | You provide* or Find | Included | Built-in |
| Integration Cost | N | N | 1** |
*Popular tools like gh are already in LLM training data, but less well-known tools require instructions.
**MCP reduces client-side integration cost to one, but requires the server to provide an MCP server.
The real strategy is knowing when to use which.
They are not competitors - they are options.
Use them together, trade off wisely.