Sculpting tools divide into things that add and move clay and things that take it away. A beginner needs perhaps four, and the large sets sold online contain many variations on the same two shapes with different handles.
Adding and moving
Wooden modelling tools with a rounded end for pressing clay into place and a pointed end for detail do most of the building work. Fingers do more than any tool, and the tools exist for places fingers cannot reach or for a crispness fingers cannot give. Boxwood is the traditional material and it survives water better than cheaper woods.
Taking away
Loop and ribbon tools cut clay away cleanly at leather hard, and carving tools with a sharpened edge cut detail into a firmer surface. The key variable is the state of the clay: soft clay smears under a carving tool, bone-dry clay chips and makes dust. Leather hard is where carving works, exactly as with trimming.
What to buy first
A double-ended wooden modelling tool, a medium loop tool, a serrated kidney for scoring joins and a rubber kidney for smoothing. That covers building, cutting, joining and finishing. Anything else can wait until a specific job asks for it, which is the same advice as for throwing tools and for the same reason.
Carving dry clay, and why not to
Carving bone-dry greenware works and produces fine dust from a silica-bearing material. If a piece has dried past the window, wrapping it in a damp cloth overnight will usually bring it back rather than forcing the issue. Where dry carving is unavoidable, a respirator and wet cleaning afterwards are the requirement.
Questions people ask about sculpting tools
What sculpting tools do I need?
A wooden modelling tool, a loop tool, a serrated kidney for scoring and a rubber kidney for smoothing.
When should I carve clay?
At leather hard. Soft clay smears and bone-dry clay chips and makes silica dust.
Are expensive tool sets worth it?
Large sets mostly repeat the same shapes. Buy a few good individual tools in the shapes you reach for.