WHat to do in this ? I saw the following question in the writing taks section of a question paper . Is it description wiritng or formal letter ?

Q.Suppose you went to receive your uncle at the airport . You lost your bag there . Lodge a complaint at the Lost Property Office , giving a description of the material , it's colour , size , shape and contents . You are Anil/Anupama ( word limit 100 ) ( 5 marks )

Is it descrption writing or formal letter ?