@dchen says

i think this is something that can be briefly explained with a tooltip that is meant to be shown once. confusing otherwise.

@Pginer-WMF

Manual annotation discoverability. The wikitext icon ("[[]]") may not convey the whole purpose of this action. It is not clear that it is about adding an annotation content manually. We can consider adding an option integrated as part of the list of search results. Similar to the creation of red links on the Visual Editor link inspector.