Having voluntary/manual tags such as envisioned in T185382: Add manual tag- messages to Wikimedia Messages for common tools/gadgets would be nice, but could we please have server-side tags for edits made with the API? This could be handy for identifying new tools, unflagged bots, etc. (Maybe even for finding some promising volunteer devs. :-)
My goal is: When I go to Special:RecentChanges, I want to be able to see which edits were not made through the traditional methods of a human clicking an edit button, typing something, and saving the changes. And I want this to be the case even if – perhaps especially if – the person using the API would rather that editors didn't notice that he's running an unauthorized spam bot, and therefore would not be willing to add a manual tag.