Final answer:
A one sentence overview of a use case is known as a brief use case description, providing a synopsis without detailed specifications.
Step-by-step explanation:
A one sentence description that provides a quick overview of a use case is called a brief use case description. This succinct summary is typically used to give stakeholders a quick synopsis of the use case without going into the detailed steps or requirements. It is valuable for communicating the essence of a use case to team members, clients, or other stakeholders who may not need to know the finer points of the use case but still require an understanding of its main purpose and scope.