An unknown is more useful than a guess
A blank field gives the team no clue whether something was missed or the requester simply does not know. Mark it as unknown so the decision stays visible.
What can remain open
The team can start while headline options, visual routes, and creative expression remain open. Exploration is part of the assignment.
An operational question can also stay open when the owner and deadline are clear. “Legal will confirm the required disclaimer before first review” is a manageable dependency. A blank legal field is an invisible one.
Put an owner on each open question
Write the question, the person responsible for resolving it, and the moment when the answer becomes necessary. “Legal will confirm the disclaimer before first review” is a manageable dependency. “Legal?” is not.
The owner can find the answer later. For now, everyone knows who has the decision.
Decide whether the team can start around it
Some gaps prevent estimation, production, or approval. Others can stay open while exploration begins. A producer should make that call with the maker, rather than treating every unanswered question as equally urgent.
Sage keeps unknowns visible in the brief so a team can review them. It does not decide which risk the team should accept.