A method of packet attribute confirmation includes receiving, at a command processor of a parallel processor, a command packet including a received packet attribute, such as a packet size, of the command packet. The command processor compares the received packet attribute of the command packet relative to an expected packet attribute of the command packet. The command processor passes one or more commands to a prefetch parser such that a summed total size of the one or more commands is equal to the received packet size of the command packet. The command processor passes, based at least on determining a match between the received packet size and the expected packet size, the received command packet to the prefetch parser. Otherwise, the command processor passes, based at least on determining a mismatch between the received packet size and the expected packet size, one or more no-operation instructions to the prefetch parser.