MCP and A2A solve different connectivity problems. MCP gives an AI application a consistent way to discover and use external data and tools. A2A lets independent agents communicate and collaborate across systems, vendors, or frameworks.

MCP connects agents to tools and context

An MCP server can expose resources, prompts, or tools to an authorised client. This is useful for company documents, CRM lookups, ticketing actions, or other controlled capabilities. Scope, authentication, data minimisation, permissions, and failure handling matter.

See MCP tool access and MCP security.

A2A connects agents to agents

A2A is useful when one agent needs another agent’s capability without sharing the same memory, tools, or implementation. A customer-service agent might request an order-status task from an order agent. Define identity, capabilities, task state, artifacts, authentication, and trust boundaries.

Use them together when the boundary is clear

A customer-facing orchestrator may use A2A to delegate a specialist task while that specialist uses MCP to access an approved CRM or knowledge source. Use ordinary APIs when a deterministic call is simpler, and a human handoff when authority or risk exceeds the agent boundary.

Related reading: MCP versus APIs and MCP monitoring.