Explanation
The business analyst should confirm that the user stories are written effectively by checking that they can be easily prioritized and are small enough to estimate accurately. User stories are short and simple descriptions of a feature or functionality from the perspective of an end user or customer. User stories should follow the INVEST criteria, which stands for Independent, Negotiable, Valuable, Estimable, Small, and Testable. User stories that can be easily prioritized and are small enough to estimate accurately are more likely to meet the Estimable and Small criteria. Estimable means that a user story should have enough information and clarity to allow developers and testers to estimate the effort and time required to complete it. Small means that a user story should be simple and concise, and it should be able to be completed within a single sprint by a single developer or a small team.
References:https://trailhead.salesforce.com/content/learn/modules/user-story-creation/write-user-stories

Identity Only is the Salesforce standard license that can be given to someone who need access only identity services, such as single sign-on (SSO). Lightning Platform, SSO License, and Salesforce License are not valid standard licenses in Salesforce. References:
https://help.salesforce.com/s/articleView?id=sf.users_license_types_available.htm&type=5