The “page tree” macro could be used to produce an automated list of every page in the space, including all nesting. Furthermore, each page could use the “excerpt” macro to declare its own annotation, and the page tree could be configured to display that.
While this would make the top-level page easier to write, it has a few flaws:
The pages would not be grouped under logical headings.
The pages would be sorted in a probably-naive order.
Annotations would need to be manually added to each page (more edits) and maintained as such --- this takes more pain, especially if applying this to an existing pile of pages.