Prompting for commercial stock photography

A stock brief is art direction written down. Evaluation words like beautiful or professional tell the model nothing it can render, because they describe your reaction rather than the picture. Concrete nouns do the work.
Name the shot, not the mood
Say what is in frame before you say how it should feel.
- ['Subject', "Who or what, and how much of them: 'adult woman, waist up' beats 'a person'."]
- ['Setting', "Where, and how busy: 'open-plan office, blurred background' beats 'workplace'."]
- ['Light', "Direction and quality: 'soft window light from camera left' beats 'good lighting'."]
Leave room for copy
Commercial images usually carry text. Ask for the space.
- ['Copy space', "'Negative space upper right' gives a designer somewhere to put a headline."]
- ['Orientation', 'A hero banner and a square social tile are different briefs. Name the one you need.']
Cut the words that do nothing
Most weak briefs are weak in the same way.
- ['Evaluation words', "'Amazing', 'perfect', 'high quality', 'professional' all say the same thing: be good."]
- ['Stacked synonyms', "'Cinematic, filmic, movie-like' is one instruction written three times, and crowds out the detail that would have helped."]
Common questions
How long should a brief be?
Long enough to name subject, setting, light and framing. Past that, more words usually dilute rather than add.
Should I use tags or sentences?
Either works. Tags are easier to revise one at a time; sentences carry relationships better. Mixing them is fine.