Understand the protocol before selecting a mobile integration.
1. Host, client and server
The host owns the AI experience and permissions. A client maintains a connection to a server. The server exposes capabilities. These are roles, not necessarily three separate physical machines.
2. Tools, resources and prompts
Tools perform operations, resources expose contextual data, and prompts provide reusable interaction templates. Their availability does not grant the model unrestricted permission to use them.
3. Android boundary
MCP is not an Android operating-system permission mechanism. AppFunctions is a separate Android capability surface; an integration may bridge them, but the protocols are not interchangeable.
Worked scenario
An Android app sends a question to a backend host. That host uses an MCP client to call a document server; the phone does not need to launch a local stdio server.
Apply it
Label the roles in a diagram for a mobile knowledge assistant. Identify where tool approval occurs.
Check your understanding
You can explain why MCP connectivity does not imply authorization. Explain the decision and show evidence from your implementation or design. If you cannot demonstrate it yet, revisit the relevant section before continuing.