properties • `type`: 'string', 'number', 'boolean', ‘positional', ‘enum’, 'custom' • `description`: A description of what the option does • `short`: A single-character alias (e.g. -n for —name) • `default`: Default value if the option is not provided • `required`: Set to `true` if the option is required • `multiple`: Set to `true` if multiple option values are allowed