The element type's description is now shown as hint text in the Tool Palette.
In addition, the Tool Palette Stencil Properties dialog now contains a new Description field. If the "Use default name and button image" check box in un-selected in the Tool Palette Stencil Properties, the Description field can be edited and that text is shown as Hint text instead of the element type's description.
Description in Element Type Properties
Element Type's Description Shown as Hint in the Tool Palette
Overriding the Element Type's Description with the Stencil Description in the Stencil Properties
Stencil Description Shown as Hint in the Tool Palette