Maxperson
Morkus from Orkus
My point is, I don't remember specifically what kind of breath weapon a dragon has. I think "what do I know about red dragons".
And in doing so, you draw upon the lore of the Monster Manual. Even if you are not consciously thinking about it, that is what you are doing. All the player is doing is letting the DM know where the knowledge came from.
But nobody has answered my question. If I ask "Do trolls have ranged attacks" (or whatever the proper phrasing would be) do I also know about their regen? Is it the same DC or automatic like the answer to my specific question?
Maybe. It all depends. And there is no "proper phrasing."