In general, we should add more rigorous authentication methods for our commandline tool. We may want to refer to the Accumulo shell implementation for password using JCommander:
Here's the JCommander password option:
https://github.com/apache/accumulo/blob/master/shell/src/main/java/org/apache/accumulo/shell/ShellOptionsJC.java#L125

And here's where this option is eventually interpreted from the control flow of main method:
https://github.com/apache/accumulo/blob/master/shell/src/main/java/org/apache/accumulo/shell/Shell.java#L261