It seems to me that the general nature of the sin and the category of it are important, to establish seriousness.
For example, it is “vile” (certainly!) to desecrate the Host. It “hurts” to hear that someone did that, but if one did do that, it should be stated, not danced around. The priest wouldn’t need the disturbing details of how the desecration was carried out, however. Similarly, it’s “vile” to engage in Satanic rituals, or to enjoy, or be silent at, mockery of Catholic rituals when that mockery is especially vile.
Violence is “vile,” (Certainly) But, for example, if there was domestic abuse, or abuse of a dependent creature such as child or animal, the priest would not need details of the physical violence enacted, just the fact that it was harsh, extreme, unwarranted. (Those could also be mortal transgressions against both the Fourth and Fifth Commandments, so if one physically abuses one’s child, that’s another dimension, versus committing violence against an equal adult.) If one commits physical violence against one’s wife, that’s certainly transgresses the sanctity of marriage as well. So the setting should be mentioned.
Similar for ‘vile’ sexual sins (if they was a vile element to them, not just a ‘standard’ sexual sin, such as fornication, adultery, masturbation, homosexual relations). A penitent could say that he or she engaged in ‘disordered sexual behavior of a particularly vile nature’ – and without going into details, because likely the details are not necessary. The penitent could further say in confession that he or she was particularly sorry for how they debased themselves to such a degree, and again the priest would get the point.
However, keep in mind that circumstances and setting are important elements for the priest to know. Thus, if the vileness of a sexual sin included sexual activity with a minor, that adds an element of seriousness, as it’s abuse of power to subject someone vulnerable to the influence of adults and without a sense of equality in the relationshiop. (So that would be at least a double sin, so to speak.) Similarly if there was a sexual sin that included violence (such as rape), that would be a double violation also.
So setting, circumstance, and degree are all more important than the details of the act.
