@Override
    public void registerHelp(HelpPrinter printer) {
        printer.option(ALLOW_UNKNOWN_TRAITS,
                ALLOW_UNKNOWN_TRAITS_SHORT,
                "Ignore unknown traits when validating models.");
        printer.param("--output",
                null,
                "OUTPUT_PATH",
                "Where to write Smithy artifacts, caches, and other files (defaults to './build/smithy').");

        if (!noPositionalArguments) {
            printer.positional(MODELS, "Model files and directories to load.");
        }
    }
Arguments available to commands that load and build models.
smithy-cli/src/main/java/software/amazon/smithy/cli/commands/BuildOptions.java