refactor: improve MCP tool execution handling with concurrent futures (#3854)

- Enhanced the MCP tool execution in both synchronous and asynchronous contexts by utilizing  for better event loop management.
- Updated error handling to provide clearer messages for connection issues and task cancellations.
- Added tests to validate MCP tool execution in both sync and async scenarios, ensuring robust functionality across different contexts.

lib/crewai/tests/mcp/test_mcp_config.py

@@ -1,4 +1,5 @@
-from unittest.mock import AsyncMock, patch
+import asyncio
+from unittest.mock import AsyncMock, MagicMock, patch
 
 import pytest
 from crewai.agent.core import Agent
@@ -134,3 +135,66 @@ def test_agent_with_sse_mcp_config(mock_tool_definitions):
         transport = call_args.kwargs["transport"]
         assert transport.url == "https://api.example.com/mcp/sse"
         assert transport.headers == {"Authorization": "Bearer test_token"}
+
+
+def test_mcp_tool_execution_in_sync_context(mock_tool_definitions):
+    """Test MCPNativeTool execution in synchronous context (normal crew execution)."""
+    http_config = MCPServerHTTP(url="https://api.example.com/mcp")
+
+    with patch("crewai.agent.core.MCPClient") as mock_client_class:
+        mock_client = AsyncMock()
+        mock_client.list_tools = AsyncMock(return_value=mock_tool_definitions)
+        mock_client.connected = False
+        mock_client.connect = AsyncMock()
+        mock_client.disconnect = AsyncMock()
+        mock_client.call_tool = AsyncMock(return_value="test result")
+        mock_client_class.return_value = mock_client
+
+        agent = Agent(
+            role="Test Agent",
+            goal="Test goal",
+            backstory="Test backstory",
+            mcps=[http_config],
+        )
+
+        tools = agent.get_mcp_tools([http_config])
+        assert len(tools) == 2
+
+
+        tool = tools[0]
+        result = tool.run(query="test query")
+
+        assert result == "test result"
+        mock_client.call_tool.assert_called()
+
+
+@pytest.mark.asyncio
+async def test_mcp_tool_execution_in_async_context(mock_tool_definitions):
+    """Test MCPNativeTool execution in async context (e.g., from a Flow)."""
+    http_config = MCPServerHTTP(url="https://api.example.com/mcp")
+
+    with patch("crewai.agent.core.MCPClient") as mock_client_class:
+        mock_client = AsyncMock()
+        mock_client.list_tools = AsyncMock(return_value=mock_tool_definitions)
+        mock_client.connected = False
+        mock_client.connect = AsyncMock()
+        mock_client.disconnect = AsyncMock()
+        mock_client.call_tool = AsyncMock(return_value="test result")
+        mock_client_class.return_value = mock_client
+
+        agent = Agent(
+            role="Test Agent",
+            goal="Test goal",
+            backstory="Test backstory",
+            mcps=[http_config],
+        )
+
+        tools = agent.get_mcp_tools([http_config])
+        assert len(tools) == 2
+
+
+        tool = tools[0]
+        result = tool.run(query="test query")
+
+        assert result == "test result"
+        mock_client.call_tool.assert_called()