When two MCP servers have tools with the same internal tool name, runningagent list MCP: list tools from server xxxx will hang, and after the tool list is (supposedly) returned, the agent cannot work properly.

During troubleshooting, issues such as network, protocol, registration, or async problems were suspected, but the real cause was that one of the MCP tools had a conflicting tool name, making it impossible for the agent SDK to distinguish between tools from different servers.

Solution

This PR implements server name prefixing for MCP tool names to ensure global uniqueness and avoid conflicts:

Prefixes tool names with server name: Tool names are prefixed with{server_name}_{tool_name} format (e.g.,serverA_run,serverB_run)
Preserves original names: The original tool name is stored in theoriginal_name attribute for actual tool calls
Maintains backward compatibility: Tool invocation still uses the original name when calling the MCP server

Changes Made

Core Implementation

src/agents/mcp/server.py: Modifiedlist_tools() method to add server name prefixes and preserve original names
src/agents/mcp/util.py: Updatedinvoke_mcp_tool() to use original names for tool calls

Testing

tests/mcp/test_tool_name_conflicts.py: Comprehensive test suite with 9 test cases covering:
- Basic prefixing functionality
- Multiple server conflict resolution
- MCPUtil integration
- Legacy behavior regression testing
- Edge cases (empty names, special characters)
- Tool invocation verification

Example

Before (Conflict)

Server1: [run, echo]
Server2: [run, list]
Result: ❌ Conflict on 'run' tool name → agent list hangs

After (Resolved)

Server1: [server1_run, server1_echo]
Server2: [server2_run, server2_list]
Result: ✅ All tool names are unique → agent list works correctly

Fixes#1167

Fix MCP tool name conflicts by adding server name prefixes

e7672a2

Problem:- When multiple MCP servers have tools with the same name, agent list MCP would hang- Tool name conflicts made it impossible to distinguish tools from different servers- This caused the agent SDK to malfunction when listing toolsSolution:- Add server name prefixes to tool names (e.g., server1_run, server2_run)- Store original tool names in 'original_name' attribute for actual tool calls- Maintain backward compatibility - tool invocation still uses original names- Handle edge cases like empty server names and special charactersChanges:- Modified src/agents/mcp/server.py: Added tool name prefixing in list_tools()- Modified src/agents/mcp/util.py: Updated invoke_mcp_tool() to use original names- Enhanced call_tool() to handle both prefixed and original tool names- Added comprehensive logging for debuggingThis resolves the hanging issue and ensures tools from different serversare properly distinguished while maintaining full backward compatibility.