Action Description, also known as Action or Description Paragraphs, are the paragraphs in a screenplay where physical actions and character descriptions are written. They are often short and sweet, e.g., "She sips from her tea." or "The lovers walk hand in hand." 

There may be times to go into a little more detail based on what needs to be described. For example, when introducing a significant character such as the protagonist or antagonist, it's often necessary to give a few lines of action description writing to communicate the unique characteristics of that character.