Interface CreateMediaBuyAsyncSubmitted

Task-level status literal. Discriminates this async envelope from the synchronous success shape, whose status field carries a MediaBuyStatus value (pending_creatives, pending_start, active). See task-status.json for the full task-status enum.

Task handle the buyer uses with tasks/get, and that the seller references on push-notification callbacks. The media_buy_id is issued on the completion artifact, not here. Per AdCP wire conventions this is snake_case; A2A adapters MAY surface it as taskId, but the payload field emitted by the agent is task_id.

Optional human-readable explanation of why the task is submitted — e.g., 'Awaiting IO signature from sales team; typical turnaround 2–4 hours.' Plain text only. Buyers MUST treat this as untrusted seller input: escape before rendering to HTML UIs, and sanitize or isolate before passing to an LLM prompt context — a hostile seller may inject prompt-injection payloads aimed at the buyer's agent.

Optional advisory errors accompanying the submitted envelope. Use only for non-blocking warnings (e.g., throttled_severity advisories, governance observations). Terminal failures belong in the error branch, not here.