AskUserRequest

Discriminator tag, always 'ask_user'.

Questions to present to the user.

ValidatedQuestion rather than Question, and carrying _validate_questions, so every rule the tool applies also applies where tui.textual_adapter re-validates this payload. A choice question with no choices would otherwise reach the client and degrade to a text box, and an empty list would render a prompt with no questions in it.

ID of the originating tool call, used to route the response back.