Spyglass MTG Blog

The battle of the AI Protocols: MCP vs A2A

Written by Rudy Sandoval | Sep 8, 2025 7:48:40 PM

Reshaping AI Forever

While obsessing over ChatGPT vs Claude, a far more consequential battle has been raging behind the scenes. Two protocols, Anthropic's Model Context Protocol (MCP) and Google's Agent-to-Agent (A2A) are quietly positioning themselves to become the "USB-C of AI." The winner won't just dominate AI development, they will control the entire AI economy.

Every major technological revolution has been defined by its underlying protocols. The internet runs on TCP/IP. The web runs on HTTP. Mobile communication runs on cellular protocols. Now, as AI agents become the dominant interface between humans and digital systems, we're witnessing the birth of protocols that will determine how these agents interact with the world and with each other.

This isn't just another tech industry squabble. This is the foundational battle that will determine whether AI development becomes an open, interoperable ecosystem or fragments into competing walled gardens. This isn't just about technical standards. This is about who controls the nervous system of artificial intelligence itself.

Understanding the Contenders

MCP (The toolbox) launched by Anthropic in late 2024, promises to be the universal connector between AI agents and the tools they need to function. Think of it as the protocol that lets AI agents "plug into" databases, APIs, and external services seamlessly. Its a way to manage the available tools and resources for an agent.

A2A (The org chart) unveiled by Google, focuses on letting AI agents talk to each other, coordinate tasks, and work together like a digital hive mind. It addresses the coordination problem—how do multiple AI agents collaborate effectively. Like an org chart for agents, it provides a framework for agents to understand their roles, responsibilities, and how they can work together to solve complex problems.

The Implications

What makes this battle truly fascinating is that it's not just about technical superiority. It's about architectural philosophy:

  • MCP represents the "enhanced individual" approach: Make single AI agents incredibly capable by giving them access to unlimited tools and data
  • A2A represents the "collaborative swarm" approach: Create networks of specialized AI agents that work together to solve complex problems

Similar to monolithic vs microservices architectures in software development, these two protocols represent fundamentally different visions for the future of AI.

The 3 Reasons Why This Battle Will Determine AI's Future

1. The Integration

Right now, AI agents are like people speaking different languages in the same room. Each AI system has its own way of connecting to external services, its own data formats, and its own communication protocols. This creates massive inefficiencies and limits the potential for AI systems to work together.

MCP wants to be the universal translator for agent-to-tool communication. Imagine an AI agent that can instantly connect to your CRM, your email system, your calendar, and your project management tool—all through a single, standardized protocol.

A2A wants to be the universal translator for agent-to-agent communication. Picture a customer service AI that can seamlessly hand off complex technical issues to a specialized technical support AI, which can then coordinate with a billing AI to resolve account issues.

In reality, we need both, but the company that wins this protocol war will have control over how AI systems integrate with the world.

2. The Developer

These protocols aren't just about making AI better they are about a valuable developer ecosystem.

MCP's Strategy: Control how agents access external tools and data

  • Every integration built on MCP increases Anthropic's ecosystem value
  • Developers who build MCP-compatible tools become dependent on Anthropic's infrastructure
  • Enterprise customers who adopt MCP face significant switching costs
  • Although compatibility is being adopted by other companies, MCP is a first class citizen in Anthropic's ecosystem

A2A's Strategy: Control how agents communicate and coordinate

  • Every multi-agent system built on A2A strengthens Google's platform
  • Companies that design their AI architecture around A2A become tied to Google's ecosystem
  • The network effects become stronger as A2A lures developers to Google Gemini models
3. The Enterprise

Fortune 500 companies are about to spend hundreds of billions on AI infrastructure. The protocol they choose will determine their AI architecture for possibly the next decade.

MCP offers immediate value: "Plug your AI into your existing systems." This appeals to enterprises that want to enhance their current workflows without major architectural changes.

A2A offers future potential: "Build AI teams that work like human teams." This appeals to enterprises that want to reimagine their operations around AI-native processes.

The enterprise decision isn't just technical it is strategic. Companies that choose MCP are betting on AI as a tool enhancement. Companies that choose A2A are betting on AI as a workforce replacement.

The Plot Twist: They're Not Really Competitors

Here's where most experts get it wrong. MCP and A2A aren't competing—they're complementary.

MCP handles the "vertical" integration: Agent ↔ Tools/Data A2A handles the "horizontal" integration: Agent ↔ Agent

Think of it like this:

  • MCP is like giving each AI agent a Swiss Army knife of tools
  • A2A is like teaching AI agents to work together as a team

The real battle isn't MCP vs A2A. It's about which company can build the most compelling ecosystem around their protocol. The winner will be whoever can convince developers and enterprises that their approach to AI architecture is the future.

Game-Changing Implications for AI Development

The End of Custom Integrations

Both protocols promise to eliminate the need for custom API integrations. Instead of spending weeks building custom connectors between your AI system and your business tools, developers will choose pre-built connectors from a marketplace.

Example: Instead of writing custom code to connect your AI assistant to Salesforce, you'll simply:

# MCP-style integration
session.call_tool(
   name='query_db',
   arguments={
     'query': "SELECT * FROM hotels WHERE city='London'"
   }
)

# A2A-style coordination
self.runner = Runner(
   app_name=self.agent.name,
   agent=self.agent,
   artifact_service=InMemoryArtifactService(),
   session_service=InMemorySessionService(),
   memory_service=InMemoryMemoryService()
)

The Rise of Protocol-Native AI Tools

New AI tools will be designed around these protocols from day one, creating a new category of "protocol-native" applications. These tools will be more powerful, more interoperable, and more valuable than traditional AI applications.

We're already seeing early examples:

  • MCP-native: AI agents that can instantly connect to hundreds of business tools
  • A2A-native: Multi-agent systems that can dynamically form teams based on task requirements
The Multi-Agent Renaissance

A2A specifically enables complex multi-agent systems that can tackle enterprise-scale problems through coordination. This will unlock AI applications that are currently impossible with single-agent systems.

Real-world scenario: A customer support request triggers a coordinated response:

  1. Triage Agent: Analyzes the request and determines complexity
  2. Specialist Agent: Handles the technical aspects
  3. Account Agent: Checks customer history and billing status
  4. Resolution Agent: Coordinates the solution and follows up

The Shocking Prediction: Why Both Will Win

Here's my controversial prediction. Both protocols will succeed, but they'll create a two-tier AI ecosystem:

Tier 1: The MCP-A2A Hybrid Systems
  • Enterprise-grade AI platforms that use both protocols
  • Maximum flexibility and capability
  • Higher complexity and cost
  • Dominated by large enterprises and AI-native companies
Tier 2: The Single-Protocol Systems
  • Simpler, more focused AI applications
  • Easier to build and maintain
  • Limited by single-protocol constraints
  • Dominated by SMBs and specialized use cases
This bifurcation will create different market dynamics:
  • Hybrid systems will command premium pricing but require sophisticated AI teams 
  • Single-protocol systems will compete on simplicity and speed but may quickly fall behind on capability and integration. 

The Protocols That Will Shape the Next Decade of AI 

If MCP is the Swiss-Army toolbox and A2A is the orchestration playbook, the durable strategy is to design for both. Standardize at the protocol layer, then compose capabilities above it. The organizations that will succeed implement an architecture that embraces interoperability, governance, and measurable value. 

A practical next step playbook: 
  1. Identify 3–5 high-leverage use cases and classify them: tool-centric (MCP) vs coordination-centric (A2A). 
  2. Establish a protocol-native reference architecture: security, identity, observability, and data boundaries from day one. 
  3. Stand up an MCP tool catalog (curated connectors, secrets policy, versioning) and a pilot A2A mesh (roles, handoffs, escalation). 
  4. Instrument value tracking (cycle time, resolution rate, cost-to-serve) to prove ROI across pilots. 
  5. Create a governance lane for agents (approval gates, drift detection, change management) and an enablement plan for your teams. 

Make the protocols your foundation, not your constraint—and treat “protocol-native” as the new “cloud-native.” When you do, you’ll be ready for whatever the AI ecosystem standardizes on next. 

For more about how Spyglass MTG can help with your Agentic Framework, contact us today.