While writing the user stories, one will always get into a dilema on 'How detailed, the user stories should be?". There is no silver bullet answer to this. The user stories should be estimatable. The user stories should contain enough information, so that one can estimate it. If the detailing is less, the conversations will be higher, which is actually encouraged in agile circles. This is perfectly allright, if the product owner has the details to provide, when the conversations happen. If tyhe product owner gets struck at this stage, without answers to the queries, then that can become a bottle neck for the project progress. If the degree of clarity of features is lower with the product owner, then it is a good idea to expand the user stories as detailed as possible. This will make the product owner think through and prioritize features.
In an off shored environment, it is always better to have detailed user stories for the initial sprints, till the team members and the product owner gets a hang of it. During the later sprints, once the product owner's and the team members understanding are in sync, then the user stories can become leaner.