When you take the trouble to put "a macro picture of a slime mold" in the image description, please, that is not a picture description and therefore, I'm sorry to write, useless.
Here are some good examples how to write short and to the point image descriptions, so many more people can enjoy your pictures: https://uxdesign.cc/how-to-write-an-image-description-2f30d3bf5546











