[BUG] Desktop app disallows SendMessage, so subagents cannot be messaged or resumed

Preflight Checklist

• [x] I have searched existing issues
• [x] This is a single bug report
• [x] I am using the latest version

What's Wrong?

In the desktop app's Code tab, Claude cannot message a running or finished subagent.

The Agent tool launches subagents successfully, and its result says to use SendMessage with the agent ID to continue the agent. ListAgents says the same. Calling SendMessage fails with the error below.

The desktop app launches the bundled CLI with --disallowedTools SendMessage. There are no deny rules for it in the user, project, or local settings. The desktop's own mcp__ccd_session_mgmt__send_message tool only targets other desktop sessions, not subagents, so a subagent can no longer be continued with its context intact. Every follow-up to a subagent now requires spawning a fresh agent and re-explaining the context.

Error Messages/Logs

No such tool available: SendMessage. SendMessage is disabled for this session, in subagents as well as here.

Claude Code Version

Desktop app 1.46388.3 with bundled CLI 2.1.260

Platform

macOS 27.0

Additional Context

Related: #92016

This issue was drafted with the assistance of Claude Fable 5.1.