Mafia tracks if you cast Conjure Cheese. It was out of synch with KoL, but if you don't cast it outside of Mafia this doesn't happen. In any case, your MP is updated at each charpane refresh, which happens very frequently.
If the failure message when failing to cast a limited-use skill is always the same, we could add it to UseSkillRequest.parseResponse(). If we have to start tracking too many success/failure messages, I don't think it would be worth it.