Estimable
If a user story is concrete enough to get an idea of how much effort it will require to complete, it is estimable. Estimates do not have to be incredibly specific, a general idea in the form of story points is close enough. If a user story is too large to give an estimate, the Product Owner should split it into multiple individual stories. Estimating user stories allows the team to know how much work they can accomplish in a single sprint. Without estimates, user stories may span across multiple sprints, or leave team members without work if they finish very quickly.
Small
Since Agile consists of short sprints, user stories must be small enough to handle within a sprint. User stories work like building blocks, with each story adding value to the product. With small user stories, the product can evolve over time, and stakeholders receive value quickly and more regularly.
In addition to being functionally small, user stories should be limited in text and detail as well. One or two sentences is plenty of detail for the team to create a working feature. Any more information than just what is necessary slows the entire development process with extra overhead. When explaining the concept for a user story, the idea should be short and simple.
Recommended Further Reading
The following materials may assist you in order to get the most out of this course: