What is the difference between an MCP and a CLI?

This post introduces the Model Context Protocol (MCP) as a transport for AI agents, contrasting it with the Command Line Interface (CLI). It details how MCP enables structured tool discovery and access with built-in access controls, making it suitable for business users and shared infrastructure. The post explains the token cost implications of MCP's pre-loading of tool definitions and outlines a decision framework for choosing between CLI and MCP based on user type and work environment. It also highlights how Hex integrates both CLI (Hex CLI) and MCP (Hex MCP server) to provide flexible agent connectivity for different use cases, emphasizing the importance of a shared context layer for consistent analysis.