When you use TCC's COPY to back up any file which has a description to another directory, it will duplicate the description in the target directory, so normally there is no need to explicitly back up DESCRIPT.ION.
Since descript.ion is normally a hidden file, to copy it you need to use the /H option (or the /a:+h option) else COPY will ignore it.
The command below ought to do what you are asking:
copy /h descript.ion description-backup.ion