Might it be an idea not to include widget descriptions by default when using advanced search?
The reason I suggest this is that the description may not make sense to a user in the search context. For example if the description says 'Enter the customer's full name' that wouldn't really be appropriate when searching.
I'm guessing that these descriptions could be removed by over-riding a template but having them not displayed by default would seem logical (to me at least!).
Paul