What is agent to agent protocol vs MCP

import os
from openai import OpenAI

client = OpenAI(api_key=os.environ["OPENAI_API_KEY"])

# Agent A sends a message to Agent B
agent_a_message = "Hello Agent B, can you help me with a task?"

# Agent B receives and responds
response = client.chat.completions.create(
    model="gpt-4o-mini",
    messages=[
        {"role": "system", "content": "You are Agent B."},
        {"role": "user", "content": agent_a_message}
    ]
)

print("Agent B response:", response.choices[0].message.content)

import os
import anthropic
from mcp.server import Server
from mcp.server.stdio import stdio_server

# Define a simple MCP server that exposes a tool
class MyMCPServer(Server):
    def handle_request(self, request):
        if request.method == "tool.invoke":
            tool_name = request.params.get("tool_name")
            if tool_name == "calculator":
                expression = request.params.get("expression")
                result = eval(expression)  # Simplified example
                return {"result": result}
        return {"error": "Unknown method or tool"}

if __name__ == "__main__":
    stdio_server(MyMCPServer())