Imagine your dentist drilling into a tooth uncertain with the work. What would be the impact of the uncertainty be to the patient? Does she have everything needed to finish the job? Will your tooth be done in an hour, a day or a week?
When people start work with questions and uncertainty, they introduce variation and instability to their work environment. Teams dealing with unstable or variable environments will not be effective nor productive.
Ask your team to build a small checklist that they, and you, will use to confirm a request is ready to be worked on. As issues happen (they always do), return to the checklist to see if you just learned something new about your checklist.
As their leader, expect and support high standards when it comes to the work teams accept. Do not ask for exceptions, nor for the team to deal with the uncertainty. Driving out variation is hard work, but the cost of variation is harder to take.
You’ve got this.