Give the prototype a specific question
A prototype should help settle a decision. Can people distinguish the services? Is the request form easy to complete? Set a task and observable criteria for each question.
Document behavior alongside screens
Explain mobile layouts, long text, empty states, and errors. Defined behavior reduces the number of decisions developers need to make independently during implementation.
Set the scope of the first release
After reviewing the prototype, separate essential needs from later features. The first release should support a complete user journey. Test that journey again after implementation: a clickable prototype is not the finished product.