Comprehensive and Detailed Explanation From Microsoft AB-620 Study Guide: The partner capability is described as an agent available only through a standardized agent-to-agent endpoint. That is the defining use case for an Agent2Agent connection. In Copilot Studio, the primary agent is configured with the external agent's A2A message endpoint and the applicable authentication details, after which orchestration can delegate shipment-tracking requests to it. An MCP server exposes tools or resources rather than an independently orchestrated partner agent, so option C changes the integration contract. An indexed knowledge source is also unsuitable because shipment status is dynamic and the requirement is delegation, not retrieval from a copied corpus. Generative responses in the primary agent would have no authoritative live shipment source and would violate the defined architecture. The A2A description should identify shipment tracking precisely so that it does not compete with unrelated agents or tools. Because external-agent support can be preview functionality, Fabrikam should also validate regional availability, authentication, error behavior, latency, and governance before production use. Study Guide alignment: Integrate and extend agents in Copilot Studio > Configure multi-agent collaboration from Copilot Studio > Create a multi-agent solution by using A2A protocol.

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