If you include artwork in your content then you need to describe the artwork. This means including a short, detailed description of the art. The description should include the physical features of the art.
An example of when you might need to do this is a guide on Renaissance art or a guide on the art in one of our libraries.
The expectation is that the title, artist, and medium of the artwork will already be mentioned in the text of the page, and therefore do not need to be included in the alt text. If this is not the case, they need to be included in the alt text.
Title: Girl with the Pearl Earring
Artist: Johannes Vermeer
Medium: Oil on canvas, 1665
A light-skinned young woman is wearing a turban of blue and yellow scarves, a large fake pearl earring, and a gold jacket. She is turned and meets the viewer’s gaze.