What makes a healthy lane bully?

So, I was thinking about the differing roles champions take in League while in lane, and I came up with a few catagories:

the farmer the burster the roamer the poker and the bully

This last category interested me the most since they are able to produce some of the most horrible feeling games, but they are commonly acknowledged as an important and healthy part of the game. I would give examples like Pantheon, Syndra, Caitlyn, and Darius as examples of lane bullies that seem to be at a good place in the game. What qualities help a champion to obtain the title of a lane bully and when does a lane bully become too good at their job? What red flags does Riot look for when deciding if a lane bully is getting too strong?

Thank you for your opinions and incite!