So we start Scrum today and start going over story points estimates.
The first story that comes up is a new screen that needs to be developed. It has 1 sentence to describe the screen and 3 user acceptance tests.
This starts a fight between the development team and the product owner.
Product owner says that stories do not need to be speced out and they will just be fleshed out during the sprint.
We say that the story needs to be completely speced out for the sprint.
But now I am starting to be unsure about who is right....
Any good articles on this that I can send to the team about how defined a user story has to be?
What happened during sprint planning?
It appears that you did not review the sprint plan to see the stories in advance of starting the sprint.
That's okay.
Stories are fleshed out during the sprint. That's the point. Relax.
Flesh out the story quickly, build quickly.
At some point, the one sentence story may become rather complex. If that's the case, break it up into something you will finish during the sprint, and stuff you will not finish. It's okay to have some stuff that was not known and did not get built.
Relax.
Do not overspecify everything. Do not specify every nuance of the story before the sprint. Just build something that will work. As quickly as possible. That's why it's called a "sprint".
Don't build everything you imagine. Build enough that the story can be performed by the user.
The point is to build something that works on schedule. If you have to adjust the scope of the story, that's okay.