Primitives, Capabilities & Utilities in MCP

In the previous examples used to explain the protocol, we focused on tools (a smarthome system that can turn on lights, adjust the thermostat, and so on). However, MCP is not just about tools. It defines a broader set of features that servers can expose and clients can use. So in addition to performing actions, MCP also supports features for retrieving data, shaping conversations, requesting model execution, or requesting user input. They are semantic categories that structure responsibility, control flow and safety between the client and the server.