Question: What is the description of the type of the company who concluded its contracts most recently?
SQL: SELECT T1.company_name FROM Third_Party_Companies AS T1 JOIN Maintenance_Contracts AS T2 ON T1.company_id  =  T2.maintenance_contract_company_id JOIN Ref_Company_Types AS T3 ON T1.company_type_code  =  T3.company_type_code ORDER BY T2.contract_end_date DESC LIMIT 1