Yes, this is possible. You can add description to the Download list template and set display:none to it, so that it won't be visible on the front end at first :
Value='<%# Eval("Description")%>' />
Then subscribe to the ItemDataBound event of the Repeater, which displays the documents and add a conditional statement, where you will set visible false to the control that displays the title and will remove the display:none style of the textfield control, which displays the description, in the case the title is the long title.
Hope this helps!
the Telerik team
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