The source – support.google.com
The company plans to launch auto-generated objects as additional creatives: Google will create titles, descriptions and other objects, combining them with those provided by the advertiser.
The option to create additional creatives is currently in beta testing.
The new feature will be enabled at the advertiser's request at the campaign level. It will only use relevant content from the specified landing page or site, as well as from existing ads and keywords in the same ad group. For example, phrases, sentences, rewriting.
Objects created this way will be added to the pool of eligible creatives for the responsive search ad. In order to display an ad in response to a search query, the system will search through all relevant properties and select those that are expected to work best.