I assume you have Lightroom, and a collection for your media...
- Export a CSV file using a third party plugin (I use jbListView).
- Copy the title field to the description field
- In Excel, append a "." to each description, so that they do not match (which would cause rejection).
Or alternatively, use JbSearchReplace. Copy title to description. Add period to end of all descriptions. -- gets the same result for stock agencies.