My Metric For Presenting In Character Or Out of Character Knowledge

I highly, highly dislike overly artificial "firewalls" as +Topher Gerkey put it between in character and out of character knowledge. Yes, I expect that for the most part players will refrain from blatantly using their own knowledge to the detriment of everyone's enjoyment of the game. But, conversely, I expect that they won't stubbornly refuse to use it when it adds to the game.

As an example, since I'm gearing up for Tribe 8, is how I've seen portrayals of characters in post-apocalyptic games finding relatively common objects like flashlights. Usually it goes down as the GM describing the object in vague details, like "It's a metal cylinder with a piece of glass set in the end." and sitting back while Twenty Questions ensues and the GM tries to lead them astray from the real answer as much as possible. If asked to draw it or show a picture, the GM hems and haws and doesn't want to because they know the players would immediately figure out it's a flashlight.

Look, just say it's a fucking flashlight. The players should be able to roleplay their characters figuring out how it works. The words, "What is this weird metal cylinder with glass set in the end?" should be coming from the players and not the GM trying to play some kind of lame game of Charades.

So, to that end here's a quick flow chart of how I make these kinds of decisions:

A Summarily Bad Idea

So I saw a post where someone suggested that the GM customize the way that something is described to the "intelligence" of the character. So if you were describing something to a player of a really dumb character, you'd use simple terms. If it was a very intelligent character, you'd load up the detail.

This is like reverse "firewalling", the act of putting up a strict barrier between in character and out of character knowledge. I think this is a bad idea on a number of levels. Setting aside the idea of tailoring information to a specific result, like for an awareness of knowledge roll (you roll poorly, you only get something vague - but if you roll well you get additional detail), the player should be the one deciding how they will parse the descriptions into what their character understands, and have their character react accordingly (and, incidentally, this is one of the reasons I believe it's impossible to completely separate IC and OOC knowledge, to the point where I don't even actively try).

Do really want the GM to talk to you like this?

I can foresee a multitude of misunderstandings and conflicts being caused around the table as a result of this. Plus, it simply seems like way too much work for too little gain. What do you leave out or include when the intelligence or whatever scores are very close to one another? Where's the cut off between talking to the player like they're a simpleton vs. just describing something normally vs. Niles Crane? What do you do when the game doesn't have a measure or attribute for intelligence?

So...tailoring the information given to a specific metric? Pretty much standard practice, I think. Tailoring how the information is given to the receiver based purely on in-game characteristics? Not really seeing how this is a good thing - unless someone can convince me otherwise.