I agree with this, filter field on reports should be able to show the description under the field for when report has many fields to set prior to generating.
This is same issue with standard list view. When the field to be filtered is ‘select’ type and when the empty value is used, that particular filter field becomes compeletely blank and the user can hardly guess what this filter is used for unless he hover the mouse on. This is okay when we have a few filter. But what if we have many filter of ‘select’ type ?