If the tapes were not created on this media server, and you cannot import the catalogs from the original server, then INVENTORY followed by CATALOG is the only way

As Ken Putnam stated, inventory + catalog is the only way unless you can bring in the catalogs from the original server.

I've run into situations where I've had a media server die and subsequent restores from media that were backed up by that media server were a pain because I didn't have the catalogs anymore.  I also had an upgrade from 12.0 to 12.5 not fully complete and I lost all of the catalogs and job history.

Ever since, I've taken to running the "Media Required for Recovery" report every week or so and saving that off to a CIFS share that is backed up.

Then if the media server dies or I otherwise lose the catalogs and I need to do a restore from media backed up by that server previously, I can consult the saved reports and find out what tapes I need.  I still need to do an inventory + catalog, but at least it's only on a few tapes rather than a whole set of them.

This has already saved me from having to catalog an entire set of tapes a few times.

Similar to the above post, if you know the media server that backed up the documents, and have a back of it, you can restore the catalogs folder from that backup and put it on the current media server.