My species of aliens happen to have hook shaped claws on their main climbing limbs, these they will sometimes use for combat. However, I was wondering, would a metal "cover" over them, that's sharpened on the edge, make a more effective weapon? They have early bronze metalworking skills.
Yes, having a metal covering on the claws would enhance their combat abilities. Metals have a higher hardness than keratin which allows metal to hold an edge much better than keratin. This means you can sharpen metal claws to a much finer point than keratin claws without running the risk of blunting the edge.
Metals are of course several times denser than bone however so expect these metal claws to be much heavier than just keratin claws, your alien may need more muscular limbs to compensate. Also, metals unlike keratin won't be able to regenerate over time. Micro fractures and damage to the metal coverings will build up over time and require manual repair and maintenance to avoid rust and corrosion.
Metal ruins your grip.
The nice thing about weapons is you can poke stuff from a distance. Guts don't get on you and if your opponent screams it is not right in your ear, like it would be if you were rassling him. Or fighting with your own little claws.
These aliens are metalsmiths. They will be making swords and spears and shields. They will be wanting to hang on to that stuff when the fighting starts and metal sheaths on your claws do your grip no favors.
No, they will leave claws bare or maybe rough them up a little bit with a file to enhance adhesion.
Claw covers will be made of shell or stone and used only for ritual combat between males.
Your species can go full Freddy Krueger is they like.
In application like this, however, it is important to keep balance between different purposes. Extra long claws, for example, can be good for fighting, but bad for pulling something out of a pocket. Also, best claws would not be as good as a weapon as a bronze sword, unless your species don't have natural talent for swordfighting.
This depends on how sharp, hard, and durable the normal claws are. If your metal is softer than the claws, it will likely get dull. If your claws are sharper, that's a major reason to avoid the metal. If they're similarly hard and sharp, but the metal is more durable, then that would be a good reason to use the metal.