Final answer:
In Agile development, high-level requirements are described as User stories. These are simple descriptions of features from the user's perspective, outlining their needs and the benefits they expect to gain.
Step-by-step explanation:
The term used to describe high-level requirements in Agile development efforts is User stories. User stories are concise, simple descriptions of a feature from the perspective of the user or customer. They typically follow a simple template such as: "As a [type of user], I want [an action] so that [a benefit/a value]." These stories help the team understand what they are building, who it is for, and why it is needed, making user stories an essential part of the Agile framework. They are also a part of the product backlog, which is a prioritized list of work for the development team, but the correct answer to your question is user stories.