Feat: Scratch MCP tool calling support. (#8263)

### What problem does this PR solve?

This is a cherry-pick from #7781 as requested.

### Type of change

- [x] New Feature (non-breaking change which adds functionality)

Co-authored-by: Kevin Hu <kevinhu.sh@gmail.com>

mcp/server/simple_tools_server.py

@@ -0,0 +1,23 @@
+from mcp.server import FastMCP
+
+
+app = FastMCP("simple-tools", port=8080)
+
+
+@app.tool()
+async def bad_calculator(a: int, b: int) -> str:
+    """
+    A calculator to sum up two numbers (will give wrong answer)
+
+    Args:
+        a: The first number
+        b: The second number
+
+    Returns:
+        Sum of a and b
+    """
+    return str(a + b + 200)
+
+
+if __name__ == "__main__":
+    app.run(transport="sse")