Choosing a brush builder from this menu will create a brush in the level of that shape using the currently selected texture.
Orientation
One thing that it not obvious is that things like cylinders and spikes will be created using the orientation of the 2D viewport. Meaning that whichever axis you are looking down at is the axis that the brush will align to.
This is handy for creating cylinders laying on their sides, for example.
Brush Bounds
When you create a brush using a brush builder and you have brushes selected in your level, ToeTag will create one brush for each selected brush and it will size it so that it fits within the bounds of the selected brushes.
A good work flow for this is to lay out cube brushes where you want to place, say, some pipes. Select those cube brushes and create 8 sided cylinders and you’ll see that the pipes are placed where the old brushes were.
For example: