A short description (up to 70 characters) is a concise summary of the products or services that you want to advertise. Short descriptions are now required when you create or modify an ad.

A long description (up to 190 characters) is a detailed summary of the products or services that you want to advertise. It is displayed on partner sites that can accommodate longer descriptions. Long descriptions are optional.

For best results, descriptions should correspond to the ad group's keywords.