MCP vs Direct API
A shared protocol many clients can use, versus a bespoke integration built for one
MCP
A shared protocol: any MCP-compatible client can connect to any MCP server and discover its tools automatically. One server implementation works the same way across many different agent clients, not just one.
Direct API
A bespoke integration written by hand against one specific service's REST or GraphQL endpoints, wired directly into the harness or application code for that single use case, with no protocol standard behind it.
Which one do you actually need
MCP trades a little flexibility for reuse: build the integration once as a server, and any MCP-aware agent can use it. A direct API integration takes more work up front but can be tuned exactly to one product's quirks, without waiting on or working around a protocol standard. Many production systems use both, MCP for the tools worth sharing broadly, direct API code for the one-off case that only ever needs to serve a single integration.