The UML class diagrams provides and narrates the class description as well as the interactions between them, especially those based on the relationships and the concept of inheritance.
In the early stages of design, attribute details and operations can be omitted or restricted to the minimum number, which is according to the requirement constituting the most apt logical concept, embedded in a particular class. In later phases, when design verdicts are concluded, a description can be extended. From the point of view of the model, description is one element that is used for a constructive view and deals with the connections between implementation elements, but on a large-scale.