The brief you write yourself

A usable brief names the audience, the one job the screen does, the density, the type and colour budget, and the constraints you will not break: maximum number of type sizes, maximum number of spacing values, contrast minimums, motion policy. Five lines, written before anything else.

Write down what you are not doing as well. Not changing the copy, not adding features, not switching frameworks. Redesigns fail by expanding, and the scope note is what you point at in three days when you have talked yourself into rebuilding the navigation.