Hello!
Audio description is a form of visual translation. It differs from everyday description In many aspects. A person who is blind, for instants, may describe what he or she sees when touching a flower, however, he or she will be the recipient of the audio description of the color and other visual cues of that flower. Everyday description does not neccessarily aim the empowerment of people who are blind or have low vision, audio description does!
To make a good audio description one must, therefore, research about what it will be described, observe what it’s being described, edit the description and write an audio description with good language.
Last but not least, If one is going to voice an audio description he or she must do it with good voice skills. See Dr. Snyder’s book The Visual Made Verbal: A Comprehensive Training Manual and Guide to the History and Applications of Audio Description to learn more about how to audio describe.