I have posted previously about what is "good enough". Steven Levy in "Legal Project Management" describes this differently and in a way which lawyers will understand. Steven notes that scope has two components, "breadth of ground to cover and the depth to which the lawyer will cover it".
A lawyer, with whom I am working on project management training, described it a little differently this week. She described junior lawyers over-researching/analysing problems as "digging to China".
Lawyers are becoming much better at ascertaining and articulating the scope of the work in terms of the breadth to be covered, rather than just focusing on the legal outcome. But it less usual to see the discussion about whether the client wants a hole sufficient to bury a bone or the tunnel to the other side of the world!
I have guidelines for preparing a scope of work, and for delegation. Perhaps I need to add the checkbox that the desired depth of the hole has been confirmed.