After a session is resumed, session.rpc.tasks.list() can return a detached shell that was started before the resume with description: "" and command: "", and without pid. TaskShellInfo types description and command as required strings, so consumers can't tell that this information is missing.

What we saw

VS Code Insiders on macOS (arm64), October 18–19, 2026. VS Code main pins @github/copilot-sdk 1.0.23-preview.5.

1. The agent started a long-running detached shell with the bash tool (mode: "async", detach: true, shellId: "component-explorer-server", with a description and a command).

2. Days later, after VS Code restarted, the session was resumed with client.resumeSession(...), then resumed again in the same client process after a model change.

3. After the second resume, tasks.list() returned this task, with a status of running or idle and no pid:

   {
     "type": "shell",
     "id": "component-explorer-server",
     "description": "",
     "command": "",
     "startedAt": "2026-10-16T16:44:19.681Z",
     "attachmentMode": "detached"
   }

VS Code only saw the shell after the second resume, and kept listing it this way for the next 8+ hours.

Expected

• A restored detached shell keeps the description and command it was started with, and its pid while the process is running.
• If those can't be recovered, TaskShellInfo marks them optional, so consumers know to handle missing values.

Impact

VS Code shows active background shells from tasks.list(). This one rendered as a row with no name, and because VS Code only offers Stop for a detached shell with a pid, it couldn't be stopped. VS Code is adding a fallback name in microsoft/vscode#342588.