On the section, Share on Facebook it's mentioned that
Currently on Pano2VR 6.1 beta3b pro, there is no Description tag generated. Actually, I don't think either Description or Author are generated.In User Data, fill out the title, author and description. The title and description will appear on all social posts (Facebook, Twitter, Google+).
The tutorial says
I agree that editing the index.html file is easy but as soon as we regenerate the HTML file, our Twitter data gets overwritten.* Currently, the metadata for Twitter is not added. but you can easily add it yourself.
Title, Description V alternate
I often find that the Title and Description I create for a tour are not the same Title and Description I wish to use for social sharing.
Can I suggest this is reviewed soon. I think Social meta data is important enough to have it's own set of fields.