The Model Context Protocol (MCP) is an open protocol for connecting AI applications to external context and capabilities. It gives an application and a server a common way to exchange information, so every model host does not need a completely bespoke integration for every data source or tool.
The host, client and server have different jobs
An MCP host is the AI application a person uses. It manages the conversation, permissions and user experience, and creates MCP clients to connect to servers. An MCP server exposes a defined set of capabilities. The protocol standardizes their communication; it does not decide whether a particular host should trust a server or grant a capability.
Tools, resources and prompts are not interchangeable
Tools let a server expose actions that a client can invoke. Resources expose context that a client can read, while prompts provide reusable prompt templates. A useful integration chooses the smallest capability that solves the job. Read-only context is not the same permission as a tool that changes a production system.
MCP is not an agent-to-agent protocol
MCP focuses on how an AI application connects to tools and context. It does not, by itself, define a complete workflow between independently operated agents. A2A focuses on that agent-to-agent collaboration problem. In one product, MCP can give an agent access to a local capability while A2A connects it to a remote agent.
Security is an application responsibility
Treat a tool description as metadata, not a security policy. Authenticate server connections, authorize each action for the current user, validate arguments, limit data access and require confirmation for sensitive or irreversible operations. Do not expose secrets through tool results, and give users a way to inspect what an integration can do.
A practical adoption path
Choose one narrowly scoped integration, document its inputs and effects, and test permission failures as carefully as successful calls. Begin with read-only capabilities if possible. Add write actions only when you can explain who authorized them, how they are logged and whether retries are safe.
My MCP developer profile
I work on AI agents and the systems around them. My MCPize developer profile is the public place to find my developer activity; follow the profile link for its current contents rather than assuming a particular server listing.