Intro
An MCP server can look like another API layer: expose existing REST endpoints as tools and call it a day.
Both receive input, execute backend logic, and return a result. But they operate under different assumptions. This two-part series explains why directly wrapping REST APIs is a bad default. This first article covers the differences in their runtime environments. The second will discuss how those differences should affect MCP design (you already know how to design a good REST API). We can see those differences more clearly by comparing the two across several dimensions.
Dimensions
The consumer
