'In a city, people are talking' is rather logical assumption, some might even say it is self evident
<snip>
And you continue your obfuscation of who decides what. In normal 5e D&D it is not assumed that a player can invent a a thing and then declare that they seek information about that thing
I haven't asserted anything to the contrary of what I've bolded.
My point is simply that
people are talking is not a fact about the PC's action, anymore than
people are building are.
If you think it is
not "logical" or "natural" that a fantasy gameworld should contain wizard's towers built by notorious wizards, well, that's on you!
Here are the difficulties for a Wises check in Burning Wheel:
Common knowledge of the subject, Ob 1; an interesting fact, Ob 2; details, Ob 3; uncommon knowledge, Ob 4; rare details, Ob 5; bizarre or obscure details, Ob 7; freaky or specific details, Ob 8
I don't remember now what the obstacle was for the Great Mastters-wise check that I made to settle the accuracy of Aramina's recollection of Evard, but it would have been Ob2 or maybe Ob 3.
The basic issue of agency, in my view, is this: if I have a character who wants to recover magical treasure (at the time, one of Aramina's three Beliefs was
I'm not going to finish my career with no spellbooks and an empty purse) then - if I have agency as a player - I will be able to pursue this goal in a meaningful way. There are different ways of operationalising this. Burning Wheel uses a mechanical framework that includes Wises checks, Scavenging checks, Circles checks, Resource checks, etc. Dungeon World uses a less formal framework of techniques and principles. From p 164:
Ask questions and use the answers
Part of playing to find out what happens is explicitly not knowing everything, and being curious. . . .
Think about time when asking questions: ask about what came before, what is true now and what might happen in the future.
Ask the Cleric about the gods, Ask the Wizard about magic and then switch it up—maybe the Thief has some ideas about the gods, too?
A game in which the player of the cleric learns about the gods only by asking the GM or making checks to learn the GM's notes; in which the wizard learns about other great wizards and their towers only by learning what is in his/her notes; is probably going to be a low-agency game.
EDIT:
There is a fundamental divide about what player agency means here. I think for Pemerton it means being able to shape the story, whereas I suspect for you (like me) it has more to do with freedom to operate freely in the setting
This is what I call
playing a RPG. Assuming that we are interested in whether the play of a RPG involves more or less player agency, defining
agency as simply the baseline act of
playing seems like it will be unhelpful.
On the topic of D&D, generally I don't think most groups assume the player can set things like plot details, monsters, etc by front loading a skill roll with a statement like "I use gather information to find news about the lich queen"
The claim about skill use is generally true. But the bigger issue is addressed in the 4e PHB (p 258):
Sometimes a quest is spelled out for you at the start of an adventure. The town mayor might implore you to find the goblin raiders’ lair, or the priest of Pelor might relate the history of the Adamantine Scepter, before sending you on your quest. . . .
You can also, with your DM’s approval, create a quest for your character. Such a quest can tie into your character’s background. For instance, perhaps your mother is the person whose remains lie in the Fortress of the Iron Ring. Quests can also relate to individual goals, such as a ranger searching for a magic bow to wield. Individual quests give you a stake in a campaign’s unfolding story and give your DM ingredients to help develop that story.
And from the 4e DMG (p 103):
Player-Designed Quests
You should allow and even encourage players to come up with their own quests that are tied to their individual goals or specific circumstances in the adventure. Evaluate the proposed quest and assign it a level. Remember to say yes as often as possible!
This clearly contemplates that the player will introduce goals for his/her PC, including facts about parents and fortresses and the like. But it is closer to Dungeon World - informal principles ("say yes") and techniques (conversation between player and GM) - than to Burning Wheel's formal framework of skill checks.