I was running an experiment on summarizing X posts around a certain topic and found this on on Agent-to-Agent pretty solid, so I am publishing this as a blog post since people ask me about the topic often. This is based on 100 recent tweets about the topic A2A (run on April 15th).
A2A is a new open protocol by Google designed to facilitate direct communication and collaboration between AI agents—even across platforms, companies, or tech stacks.
It’s not a replacement for MCP, but rather a complementary layer that focuses on agent-to-agent coordination, where MCP focuses on agent-to-tool interaction.
🧠 Core Concepts from the Community
🧩 How A2A Works
- Agent Roles:
- Client Agent: Initiates tasks
- Remote Agent: Receives tasks, executes them, and returns results (called artifacts)
- Task Lifecycle Support:
- Tasks can be immediate or long-running
- Agents track and update each other on task status, outcomes, and progress
- Security:
- Secure by default: Built-in authentication and authorization
- Agents must authenticate before interaction (enterprise-grade protocols)
🔧 Design Principles
- Cross-agent communication — enabling collaboration even without shared memory or context
- Task-driven structure — work is encapsulated into clearly defined tasks and results (artifacts)
- Resilience and Continuity — supports long workflows, useful for enterprise ops
- Complement to MCP — A2A models agents as MCP resources or “AgentCards”
- Open interoperability standard — with 50+ launch partners (e.g. Google, Salesforce, Intuit)
📈 What People Are Excited About
| Theme | Highlights |
|---|---|
| 🛠 Enterprise Interoperability | Seen as a key step toward standardizing multi-agent collaboration across orgs and vendors |
| 🤖 Composable Agent Ecosystems | Encourages workflows where agents dynamically assign tasks to one another |
| 🔐 Security Focus | Secure tokens and authenticated communication are praised |
| 🧩 MCP + A2A Together | Most posts suggest MCP is for tool orchestration, and A2A is for peer coordination |
❗️What People Are Questioning or Exploring
| Concern | Notes |
|---|---|
| 🧠 Tool-trigger complexity | Some worry agent-to-agent systems may exacerbate the challenge of choosing the right tool or agent |
| 🧪 Redundancy with MCP? | A few posts question why A2A is needed if MCP can already handle multi-agent tool chaining |
| 📚 Still Early / Confusing | Users admit it’s unclear how best to integrate A2A into real systems yet |
🔄 Example Integrations Mentioned
- A2A agents modeled as MCP resources
- Integrated with systems like Google ADK, Claude, Anthropic, Salesforce, and Solana trading backends
- Used in no-code platforms and agent builders
- Backed by Google with >50 partners
🧭 Final Takeaway
A2A is emerging as a foundational layer for multi-agent communication. While MCP enables structured tool use, A2A formalizes the social contract between agents—supporting negotiation, delegation, security, and collaboration.
The future likely includes A2A+MCP hybrid systems, where:
- MCP handles tool execution
- A2A handles agent collaboration
- Both are needed for robust agentic workflows