Small Transport
Air Traffic Control Fully Certified
Air Traffic Control Time Certified In Pos 1 (yrs) 8
ATC Issue All Types; Deviation / Discrepancy - Procedural Published Material / Policy; Deviation / Discrepancy - Procedural Clearance; Inflight Event / Encounter CFTT / CFIT
Air Traffic Control Issued Advisory / Alert; Flight Crew FLC complied w / Automation / Advisory
Human Factors; Procedure
ZLC called to coordinate Aircraft X on VOR A approach to ZZZ. ZLC said they would clear the aircraft on the approach and then ship the aircraft to TWF for arrival to ZZZ. Aircraft checked on with me and verified that ZLC had cleared on the approach. A few minutes later ZLC called and said they observed the aircraft was descending and said they may need a low altitude alert. Altitude alert was given to the aircraft and altitude to maintain and the aircraft said the terrain was in sight and was providing visual separation from terrain. Brasher warning was issued and Aircraft X arrived at ZZZ without further incident. I called ZLC afterwards and ZLC said they had issued the approach clearance to the ZZZ airport. They did not include a crossing restriction for the aircraft to the IAF; rather they thought the pilot would adhere to published altitudes on the airway until reaching the IAF. In the future; I will probably not issue an approach clearance or approve an approach clearance without providing altitude guidance to the IAF regardless of route.
TWF controller reported an IFR handoff; improperly cleared for an approach; resulted in a descent below the MVA.