ZBRUSH: Delete Tool

It took a bit of Google searching for something as simple as this, but it turns out the only way to delete a tool from your 3D Meshes palette is to delete it in the SubTool menu.  It's a bit counter intuitive considering all your subtools are nested under that tool / mesh, but once you delete all the subtools on that mesh, your tool has been successfully deleted from 3D Meshes palette.