Hello Hbdekor -
The only way you can import a template using a .csv file would be to include the entire HTML for the template in your description. I am not entirely clear on what you refer to as the "Description" tag, so I would strongly encourage you to file a support case from under the Help tab of the site letting us know what trouble you are encountering with your .csv upload so we can look into the specific difficulty you are encountering. We may then ask you to send us the file you are attempting to upload for review if it becomes necessary.
- Craig