The invention relates to a rotary tool as well as to a carrier and a cutting insert of such a rotary tool. The carrier comprises a seat, which comprises several lateral surfaces, between which the cutting insert can be inserted. The cutting insert comprises, for each of the lateral surfaces, a contact surface which abuts against the respective lateral surface in an inserted state. At least one coolant channel is formed, which comprises a first partial channel and a second partial channel, which adjoins the first partial channel, wherein the first partial channel proceeds within the carrier up to an outlet opening, wherein the second partial channel proceeds within the cutting insert from an inlet opening up to a coolant outlet, wherein the outlet opening and the inlet opening form an interface for transferring coolant from the carrier to the cutting insert. The outlet opening is arranged in one of the lateral surfaces and the inlet opening is arranged in one of the contact surfaces.