Beware of scripts that describe feelings, character's thoughts, motivations and purple passages. The writer may have done this to help their thought purposes, make the script attractive to a backer, or describe to the actors their motivations. This can be a trap for the director. So too can the other extreme, which would be for the writer to assume that what he or she has not described is inherently obvious to the director. The director's job is to translate who, what and why into how, by action and by dialogue.
Some modern directors like to improvise on the set.
The best is half way between these Two extremes. Sometimes writer and director work together. I rough it out and give it a structure. I will try and think out the purpose of each scene and this helps towards giving the idea a definite shape, a rhythm of development. If this development seems to hold out in a rough form, I then start writing a much more detailed description of the action.