The phrase "official description" refers to the accurate and authorized explanation or summary of something given by an authorized source or entity. Full definition
After an early version of the film's plot was revealed in casting notices, this new announcement offers a more detailed, official description of the film. (newsarama.com)
You can check out the videos, as well as official descriptions for each game, below. (heypoorplayer.com)
The difference in coat type (the long coat or the smooth coat) is the only official description used to identify a difference within this breed. (chihuahuaclubofamerica.org)