Has it been prohibited for a wife to mention to her husband the good qualities of another woman?

Yes, it has been reported from the Prophet, peace and blessings be upon him, that he forbade a woman from directly interacting with another woman and then describing her to her husband. This is out of fear that the husband might be impressed by the description and be tempted by the described woman, or that he might divorce his describing wife. Direct interaction here means touching or observing her body, and "describing" is precisely and clearly detailing what she saw of the beauty of her skin, which could lead to the husband's heart becoming attached to her and to temptation occurring.