The web Claude wouldn't tell me, but Claude Code had no reservations:

   EndConversation (deferred tool): use only for sustained user abuse directed
   at the assistant, or when the user explicitly asks to see it demonstrated.
   Load the full guidance via ToolSearch("select:EndConversation") before using
   it.

https://snowday.s3.amazonaws.com/store/6097125d0a169554063dd...