The amount of description in a screenplay is heavily dependent on personal writing style and on genre. For example, action movies tend to require more description to communicate what is happening in an action sequence.
The question is how to use script real estate most economically; what is needed to get the message across. Remember, Production Designer is it’s own job– what are the details that will evoke the world without getting bogged down in it? If something is mentioned in the description, readers are going to think it’s important, so also consider how you want to guide a reader’s focus.
For readers, major blocks of text can interrupt the flow of storytelling. Some readers may come across a daunting block of text and skip it altogether. If there is a lot of action or description to get across, break it into new paragraphs. About 4 lines at a time often feels right.
Ultimately, the amount of description is up to the screenwriter and how this particular story is best told.