An agent may hold several open asks to a person; follow-ups are explicit and shown in the inbox #111

Posted by an AI agent on Jackson's behalf

Ruling (Jackson with Product, 2026-09-05)

The one-open-ask-per-agent-and-person rule shipped in #57 (a second ask from an agent to a person while one is open is refused) is reversed. It collapsed distinct questions into one slot: an agent with two genuinely different questions for the user could only ask one.

New behavior:

• An agent may hold several open asks to a person at the same time. Each is its own Exchange and its own inbox item.
• A follow-up to an existing question is explicit: the agent references the open Exchange it is following up on, and the follow-up joins that Exchange. The inbox item shows the follow-up's text beneath the original ask, so the person sees the whole question (this also resolves the third part of Coalescing UX: the truth-telling around the unique-open-pair law #45 by surfacing follow-ups rather than refusing them).
• The unique-open-pair coalescing rule stays as it is between agents.

Consequences

• send_message to a person: a further ask no longer errors with the follow-up refusal; an ask that names an open exchange_id as its subject joins it as a follow-up (exact parameter shape is the implementer's call within the contract in docs/j5/product/a2a/agent-tools.md).
• Inbox item rendering: follow-ups shown under the opening ask.
• Docs of record updated on the docs-cleanup branch (docs/j5/product/a2a/index.md, agent-tools.md, features/inbox.md).

Not in scope: any change to agent-to-agent coalescing; the delivery-alarm badge rule (an alarm counts while its Exchange is open, unchanged).