Let me be more clear. (The purple text in the image was terse.)
The definition must be selected, in the “In Model” definition list, in the Components Manager, for the “name” and “description” fields to be populated.*
This is because they are edit fields, not just display boxes. The user can globally change the definition’s name and / or description at any time. (I said this in the thread above. You cannot stop them from changing these fields, but you can detect the change via a Ruby observer.)
It would be a good feature request for the definition’s description to appear (as READONLY) in the EntityInfo inspector, when a component instance (and maybe a group,) is selected.
* Why? Because, selecting a component definition interrupts the current tool, and activates the component placement tool with the selected component attached to the cursor. This can be annoying if the user is only in “inspection mode” and not really wanting to place more components. (Get used to hitting the ESC key alot, to throw away the component, and return to the SelectionTool.)
In the EntityInfo inspector, if the two shadow checkboxes were moved down to the left under the other two (Hidden & Locked,) there’d be a nice place for the description display.
Groups are a bit special in that their definitions are hidden in the UI, but programmers can change their definition’s names and descriptions via code. (The group instance’s description methods are proxies to it’s definition’s description.)