Interaction Patterns & Response Handling
Requests, responses, and notifications; how results and streams flow between client and server.
Domain 3: Interactions & Execution
Exam weight: 26% — the largest domain
This domain covers how MCP participants actually communicate: request/response patterns, notifications, streaming, error handling, the full tool invocation lifecycle, and the protocol primitives.
Competencies
Section titled “Competencies”Error Handling
Protocol-level JSON-RPC errors vs tool execution errors, and how each is reported and recovered from.
Tool Invocation Lifecycle
The complete life of a tool call — discovery, invocation, progress, cancellation, and results.
Protocol Primitives
Server primitives (tools, resources, prompts) and client primitives, with their key methods.
Learning objectives
Section titled “Learning objectives”After studying this domain you should be able to:
- Distinguish requests, responses, and notifications, and when each is used
- Explain protocol-level vs tool-level errors and how each is reported
- Walk through the complete lifecycle of a tool call, including cancellation and progress
- List the server and client primitives with their key methods