@BrentToderian the best advice I’ve ever gotten about how to write a good #AltText is “pretend you’re describing the image to a friend over the phone.”
Don’t make “brief” your goal. Make your goal to communicate the same information, via text, that the image is communicating. If the image is meant to evoke a feeling, describe that feeling. If certain details are important to painting a picture or understanding the image, describe them. If the details are secondary, feel free to leave them out