The documentation for --add-launcher currently states:

--add-launcher <launcher name>=<file path>
Name of launcher, and a path to a Properties file that contains a list of key, value pairs (absolute path or relative to the current directory)

The keys "module", "main-jar", "main-class", "arguments", "java-options", "app-version", "icon", "linux-app-category", "linux-app-release", and "win-console" can be used.

These options are added to, or used to overwrite, the original command line options to build an additional alternative launcher. The main application launcher will be built from the command line options. Additional alternative launchers can be built using this option, and this option can be used multiple times to build multiple additional launchers.

The --description option provides a string that, among other things, is embedded into the .exe. The Windows Task Manager will show this description on the "Processes" tab instead of the exe name.

Also, hovering over the .exe file will result in a popup that shows the description string for "File description:". The different launchers should be able to have different descriptions as this information can be helpful for the end user to determine what file to run.

Without the ability to override this for different launchers, they all show the same description which can be confusing.