The problem with just leaving it open like that is, "power" in any derivative of D&D is usually understood to mean level/HD- or combat statistics. None of which can be increased by simply rolling Knowledge checks and following the advice thus gained. Items are one of exactly two ways to directly change the combat statistics other than gaining levels (and feats) via experience points, so the most immediate way to increase power using skill checks is to point you towards items which will increase your power. The other way is spells (or similar effects), which can be dispelled unless they're Instantaneous duration. I suppose in theory you could have a Knowledge check point towards a long-lost spell, but that requires tinkering with the skill check rules- by RAW a 9th-level spell is only DC 34 at the highest (for a spell that just targeted the person making the check). Just plain knowing about the spell's existence would obviously have to be less than that, since knowing of a spell's existence is logically necessary to identifying the spell's name from its effect.
If you have a different definition of "power" than level/HD/combat stats, then suggest it; holding back will not get you more posts. Within the game system as written, items and spells are the only ways Knowledge checks could point you towards direct power increases. I don't count Planar Touchstones because that requires taking a feat- which gets us back to requiring XP again. Gaining XP isn't something a Knowledge check can directly do for you unless you change the world/rules to allow it. Which leads us back to my suggestion about the world/setting being important- if the world has special mechanics somewhere, somehow, like the way gods are born/made, then that can work. But it's not setting-neutral.
Creativity in an open environment usually requires a hook to hang itself on before anything starts to gel; it's like crystal growth that way. Once the ball gets rolling, others build on it and stuff starts to filter out and connect together to make Something Cool.