How can I copy flickr descriptions to exif?

I need to move most of the albums from one Flickr account to another. There do not appear to be any tools to do this directly. I am left with downloading them, then uploading them to the other account.

  • If I download direct from Flickr the images do not retain title, description, etc.
  • If I use the Flickrdownloadr tool it copies this metadata into a separate json file, but in such a way that exiftool reports it as a ‘File Format Error’ and won’t process the files

I need to merge the metadata with the image files, somehow, some way. Fifty Google searches have not resolved this issue yet. Short of downloading dozens of albums and manually copy-pasting this metadata, one file at a time, is there any other way to achieve my goal?

My OS is Kubuntu. I have a Windows machine available if needed…