how to restore gconf-editor key documentation?

[TomRoche]

In a helpful response to a different question, CptMidnight shows a screenshot of his gconf-editor



But when I browse to that key, I see only



And, in a brief bit of sampling, I see no documentation or schema for any keys in my gconf-editor. How to fix?

Note that I'm currently observing this in MATE after updating to UP4, but I'm posting in this forum since I haven't yet checked on Cinnamon and GNOME3. (Restarting is not convenient for me at the moment.)