Agentic Builder Path / Agentic Systems
MCP and A2A in Plain English
A fast explanation of how agents discover tools and collaborate with other agents.
A fast explanation of how agents discover tools and collaborate with other agents.
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Executive note
Core Idea
Agentic systems need ways to connect to tools, data, services, and other agents. Without common patterns, every integration becomes bespoke and difficult to govern.
MCP and A2A are part of the move toward more standard agent infrastructure.
Section 2 of 6
MCP
MCP, the Model Context Protocol, gives AI applications a common way to discover and use external capabilities.
Instead of each application inventing a custom connector for every source, a team can expose approved capabilities through a consistent protocol.
Think of MCP as a way to say:
- What tools are available?
- What inputs do they expect?
- What data can they read?
- What result do they return?
- Which user or agent is allowed to use them?
Section 3 of 6
A2A
A2A focuses on agent-to-agent collaboration. The idea is that one agent may need help from another specialized agent.
For example, a learning assistant may ask a credentials agent which badges are available for a role, while a content agent drafts a quiz from approved material.
The important point is not that agents chat for fun. The point is controlled delegation between specialized capabilities.
Section 4 of 6
Why Standards Matter
Standards reduce coupling. They make it easier to replace a tool provider, reuse a capability, centralize governance, and observe what is happening.
They also help avoid a common failure: building one large agent that knows too much, can do too much, and is difficult to test.
Section 5 of 6
Recommended Practices
- Start with one or two high-value tools before publishing a large catalog.
- Require identity propagation so tool decisions know who the user is.
- Keep authorization in the system, not in prompt wording.
- Log tool discovery, tool calls, denials, errors, and outputs.
- Treat agent-to-agent delegation as a privileged action.
Section 6 of 6
Remember This
MCP helps agents use tools and data through a common interface. A2A helps specialized agents coordinate.
Both are useful only when combined with identity, authorization, telemetry, and clear ownership.