Buyers should prioritize OBD II/EOBD compatibility and ensure the device supports multiple protocols such as CAN, J1850, and ISO9141. For professional use, look for bi-directional control (active tests) and ECU coding capabilities. The hardware should feature a high-resolution touchscreen (at least 7 inches), a quad-core processor, and a minimum of 32GB storage to handle extensive vehicle software databases. Additionally, verify if the tool supports Full System Diagnosis (ABS, SRS, Engine, Transmission) rather than just basic code reading.