I am trying to optimize a map I am working on, I understand the placement of hint brushes, but I notice some of these optimizing brushes have just hint texture, and some have hint with one side being the skip texture. Does anyone know how this works exactly, why it is so, and how I should position the skip side to optimize?

It should be a brush with skip on all faces except one, which has hint. The side with the hint will cut the leaf.