MCP is used to connect AI agents to tools.
Not only that.
Tools are just one of the three core primitives an MCP server can expose.
These three components are:
Resources - data/context that the AI application can access
For example, an email, a file, a database record, or documentation.
Prompts - reusable prompt templates for specific interactions.
For example, a predefined "review this pull request"; prompt.
Tools - functions that the AI application can execute.
For example, send an email, create a Jira ticket, or book a flight ticket.
So a better mental model is:
Resources ->Read
Prompts -> Guide
Tools -> Do
This distinction matters because when you think of MCP only as a way to connect tools, you miss a significant part of what the protocol actually provides.
Now, the question for you is
Why not just put the prompt in the agent's system prompt? Why access it through MCP?
