To do productive, it is nice to have a plan. It is also important that the plan clearly guide all team members in knowing what needs to be done. In that sense, it is possible to design a project plan and still have the team not quite clear on the tasks that needs to be done.
I find that this is very important for professional and intellectual work. It is very dangerous in a project plan to write: “analyze ….”. Why? Because it is possible to analyze almost to infinite, and it is also something very difficult to assess if the analysis is going in the right direction or not.
It is important to name a task in a way that makes it clear what should be achieved.
PMI posted an interesting article on the subject of naming a task
Yes, I have always seen productivity boost when everyone in a team understands what we need to do and why.