Comparison
A2A vs MCP: how they differ
MCP connects an agent to tools; A2A connects agents to each other. Different axes — they complement.
In short
Different axes of interaction: MCP is agent ↔ tools, A2A is agent ↔ agent. Not competitors — adjacent layers.
What each is
- MCP (Anthropic) — connects an agent to tools, resources, and prompts. “Give the agent hands.”
- A2A (Google) — agent-to-agent communication: an orchestrator finds a specialised agent by its skills and delegates a task. “Give agents a common language.”
Side by side
| MCP | A2A | |
|---|---|---|
| Axis | Agent ↔ tools | Agent ↔ agent |
| Unit | Tool / resource | Skill |
| Card | MCP Server Card | A2A Agent Card (/.well-known/agent.json) |
| Author | Anthropic |
Key difference
MCP answers “what tools does the agent use.” A2A answers “what tasks does the agent solve and how do other agents find it.” MCP faces inward (tools); A2A faces outward (discovery and delegation).
Do both
Yes: MCP gives your agent tools, A2A makes it discoverable to orchestrators. Agent Skills is the shared bridge: the skills in an A2A Agent Card describe what the agent can do.
How to verify
A scan checks for both an MCP Server Card and an A2A Agent Card — both cards in one report.