MCP vs. API vs. CLI: How should AI agents connect to your app?

This post argues that an MCP server should be the first choice for making a web app agent-friendly, because MCP standardizes both server and client behavior, lets the client handle OAuth so the model never sees the token, and can route destructive-action confirmations directly to the human via elicitation. REST APIs remain better for scripts, bulk jobs, data exports and integrations that run without an agent, while CLIs suit agents with a shell working with local files. The author recommends putting business logic in operations and exposing them as thin adapters over MCP, REST and optionally a CLI, using the open-source Linkly link shortener as the example.