I recently found myself debating about the usefulness of acceptance criteria in a user story. Bear in mind that the team in question is not a feature team, it is a technical component team (if that changes things).
The team members have been writing a page or two with things that they will build; not so much of a spec document, as a definition doc of what needs to be done. In there, it's quite clear what the scope of the story is. So in effect, the verdict was that there was no need to worry about acceptance criteria (in the Jira ticket for example).
This seems to be working with the team, as there was no ambiguity on implementation (and if there is any, the team will discussing amongst themselves), so I am puzzled about what would the acceptance criteria add to this user story, and whether it is worth enforcing that.