We talked about doing exactly that in my group. The problem is this clashes with the "don't hide essential information behind a check" guideline.

Like, you can say a nature check of 15 tells them some information about the troll. Let 's leave aside the problem of "well the dm is just being dramatic when he said it cuts known knights like paper" problem and say you tell the players some usable ballpark numbers. Cool, they can make an informed decision that something that swings at +10 and has an average dpr of 25 is too much.

But what if they fail the check? Do you shrug and say they don't know? Do you just let them blend themselves with this troll? That puts us back to square 1, really.

A working solution might be degree-of-success (which 5e tends to underuse). A very high check might give you the actual to-hit, damage dice, ac, but even a very low check might give something like "it can easily exceed your HP per round in damage" or something vague but mechanically grounded.

You would need to be clear when you're giving actual information and not fun flavor.