Thanee said:
And that is exactly where I make the cut different, as to what constitutes information gathering (or gaining).
When you look at a polymorphed creature with True Seeing you do not gain the information how this creature looks like, instead you gain the ability to see the creature as it is. This in turn gives you the information how the creature looks like, but that is not an effect of True Seeing. Your own eyes give you this information.
A hypothetic Detect Invisible spell would give you the information, that there is an invisible creature around, while the spell See Invisible lets you see inivisible creatures, but does not give you any information.
And, if you do not make a cut like this, then pretty much every spell or effect would be an information-gathering spell or effect, since you can indirectly gain various information about a subject with just about anything.
The problem is, your method has no real rhyme or reason to it (i.e. no rules).
For example:
DM: "He sees you with his True Sight spell."
Player: "How? I have Mind Blank up."
DM: "Because he divines you as you truly are."
Player: "But, divining is a divination."
DM: "I meant he gets information on what you look like."
Player: "But, that means he is gathering information on me."
DM: "I meant he breaks your invisibility with True Sight, but that is not targeting you specifically."
Player: "Then how come my See Invisibility did not work last week on the Mind Blanked Invisible BBEG."
DM: "Err, cause See Invisible is not as strong as True Sight."
Player: "But, it did not target him specifically either."
DM: "Shut up. I'm the DM. I know how it works."
Player: "Whatever. Can you make a list of which works and which do not?"
DM: "No. Instead, Mind Blank does not work for PCs in the game, only the BBEGs, and hence, I do not have to explain it."
Player: "Yeah, whatever. I Fireball his butt."
DM: "That doesn't work either."
Player: "What?!?!?"
The point is, if you make it the partial solution, you have to come up with why it does not REALLY gather information in some cases and why it does in others. And, you have to come up with a (house rules) list (that makes sense) as to which spells it stops and which it does not.
Otherwise, there are no set rules to follow, just DM whim.