Desktop: let a Code session start a normal new session with a prompt, model and effort, with no click

Where: Claude desktop app on Windows 11, Code tab, local sessions.

Problem

Every tool call re-sends the whole conversation, so long-running work gets expensive. The fix is a handoff: save state, then continue in a fresh session that starts small. In the terminal this is fully automatic (a script launches claude with the prompt). In the desktop app a session cannot start a normal session by itself:

• mcp__ccd_session__spawn_task makes a chip, and the user must click it.
• No start_session or hand_off_to_session tool is exposed, although the descriptions of detach_session, stop_session, set_session_model, set_session_effort, open_session_in and list_sessions all refer to them (see also #99393).
• Workaround found: an ad-hoc scheduled task started with run_scheduled_task, then set_session_model and set_session_effort, then send_message. It needs no click, but the new session is a "routine run". It shows only under Routines and cannot be moved, grouped, pinned or detached (move_sessions and detach_session refuse it). It also needs a persistent routine, and two of them so a hop can start the next hop.

Request

Expose a tool, for example start_session, with these inputs:

• prompt (first user message)
• model and effort
• cwd or worktree option
• permission_mode

It should create an ordinary top-level session in the sidebar under the same project, with no click. Approval can follow the existing rules: a model or effort above the caller's own asks the user first.

Why it matters

Automatic fresh-session handoff is the main way to control token cost on long tasks. Without it, desktop users either click each handoff or fall back to the terminal.

Verified

set_session_model and set_session_effort already work on a session created this way. Both apply from the next turn, so a created session should take them before its first turn.