Stage directions are an essential element of any script. Without them, your script will be nothing but a choppy mass of dialogue. They help establish your show's world and, crucially, they tell the producer - and, later, the director - what is going on. They orientate the reader (and the writer, too).
Some stage directions will be breezy and brisk - zooming along! - breathless, and energetic - full of pace and verve and -
oh Gosh, what's this?! -
OTHERS WILL BE PRECISE. PRACTICAL, VOICELESS. TO THE POINT.
It's partly a matter of style. But also a matter...