I know this is trying to fix an issue, which would probably be "easier" done just by doing the right thing. The issue is, that sometimes our developers need to make subtasks into main tasks and drag them into the sprint, as well as making new tasks on behalf of ongoing work with third parties. They're suppose to do ad hoc refinement and issue story points for these tasks, but once in a while they just fail to do so.
I have tried finding the answer elsewhere without much luck: Is it possible to make a restraint on sprints, so that tasks can not be dragged into them IF they do not have any story points on them?