“We already have APIs. Why do we need MCP?” It is the most common question we hear — and it is a fair one.
What an API does well
An API is a contract between two programs. A developer reads the documentation, writes code that calls specific endpoints in a specific order, and handles every reply. For a fixed job that runs the same way a million times — processing payments, syncing inventory overnight — nothing beats it. It is fast, predictable and cheap.
Where APIs struggle with agents
An agent does not follow a script you wrote. It decides what to do based on what you just asked. With raw APIs, someone still has to teach the agent about every endpoint of every app, one integration at a time. Ten apps and three agents can mean thirty separate wiring jobs — and every app update can break one.
What MCP adds
- Self-describing tools: the server tells the agent what it can do, in a format the agent already understands.
- Runtime discovery: the agent finds the right tool when you ask, not when a developer planned for it.
- One connection, many agents: connect an app once; Claude, ChatGPT, Hermes and others can all use it.
- A standard for permissions: approvals and access scopes work the same way across servers.
Under the hood, most MCP servers still use the app’s API to do the actual work. MCP is not a replacement — it is the agent-friendly layer on top.
The honest answer
Fixed pipeline that never changes? A plain API is probably fine, and we will tell you so. Flexible, everyday work across lots of tools — “handle my enquiries”, “prepare my weekly report”, “keep my content calendar moving”? That is agent work, and that is where MCP wins by a mile.