The screenshots below demonstrate the point I am making about Facebook pages having sparse metadata. In addition, the sparse metadata that exists is barely comprehensible to either a human or machine, even though existing open standards are in place for addressing this issue.
Here’s a Facebook news post as my exhibit. I use the OpenLink Structured Data Sniffer (OSDS) browser extension to visualize existing metadata in the sample HTML doc. In addition, I use the dokie.li browser extension for incorporating additional metadata via inline edit or via its metadata injection control.