Estimate the consequence of being wrong
Identify which part of the result depends on the unknown and what could happen if the assumption is incorrect. A choice affecting only formatting is different from one that sends messages, changes access, or modifies production data.
Check whether the answer already exists in the task, project files, or accessible records. If the uncertainty is limited and a safe check is available, perform that check instead of interrupting the user.
Ask a focused question
When a decision still depends on the user, explain the two or three practical options and their consequences. Ask only for the missing choice; avoid asking the user to repeat information already available.
For reversible choices, state the assumption in the result and make it easy to change. If the assumption is rejected, update all dependent work rather than treating the correction as a new unrelated request.