It's hard to tell which required argument is not given.

[XiangyuG]

Currently, most of required arguments are positional arguments, and if one is not given, the program says the last one is missing.

We can change everything, except program file, to named arguments and make them required.

The advantage we get is we'd get better error message when a required argument is missing or wrong, but we have to manually specify their names in commands. So the command itself gets longer.