Cat intelligence is actually a pretty interesting topic in that the majority of studies on the subject basically have to end in the conclusion "we just don’t know" because cats are among the most uncooperative research subjects of all time. We know a great deal of cat sight, having used cats as the archetype for a vision-focused vertebrate/mammal, but we still know very little about what really goes on inside the cat mind.
Cats can be incredibly, frighteningly intelligent. When it benefits them. You try to get them to do something solely for your own amusement, and you’ll get squat. Most dogs are motivated by praise, but cats are generally only motivated by personal gain of some sort.
Potioneers sometimes have need of “claws” such as these in order to more easily manipulate small and delicate ingredients and protect themselves against those which are dangerous but still require extreme delicacy, which cannot be achieved while wearing a glove. Some wix have beautifully ornate sets of “claws” crafted for them.