If you're looking for rewards from a monster, you can do research to find out what it offers. Puzzlefox mentioned that the hunting horn could be a viable option for cutting tails. This type of weapon is known for its strong hits and blunt damage, which can break parts of tough monsters. In previous Monster Hunter games, the hunting horn had a small stab attack that could sever limbs (by pressing back+attack after any initial attack).
Additionally, in the third game, the forward stab (activated by pressing Select) could cut tails; as seen in this video. Starting with Portable 3rd, the damage formulas were changed and the Hunting Horn dealt more sustained damage than the hammer. Even the attacks that both weapons seemed to share, such as the Superlibra (Triangle+Circle), were weaker in the Hunting Horn. The punch of the grip (I can't remember its real name) is meant to reduce damage, so it's theoretically possible to cut tails with it, but it's unlikely to be very efficient and, depending on the monster, almost impossible.
The hunting horn (Shuryōbue) is a weapon that was first introduced in the second generation of the Monster Hunter series. Cut (cut) damage is done by swords in Monster Hunter World, which is most of the weapons in the game. Some monsters have brittle tails that require blunt weapon damage, but most monster tails in MHW can be cut with cut damage.