This happens specifically when trying to debug a specific C# xUnit test using VS Code Insiders and GitHub Copilot.

How to reproduce:

1. Ask the GitHub Copilot agent to place a breakpoint and start debugging a specific test in a C# xUnit project using VS Code Insiders.
2. The agent successfully runs add_breakpoint tool.
3. The agent makes a tool call to start_debugging using input like that:

{
 "fileFullPath": "/path/to/project/test.cs",
 "workingDirectory": "/path/to/project",
 "testName": "Test_Should_Do_Something"
}

4. The agent keeps waiting indefinitely for the tool call to return any results.