If an entity has a descriptive text field about a sentence long, call it summary.

If the entity has a longer descriptive text field, call it description.

git's treatment of commit messages can be described this way - the first line of the message is the commit's summary, and the body is the commit's description.

It is astonishing how many systems use short_description and long_description, or even clumsier names.

Don't do that.