Does Mind Blank stop a monster's special senses like Truesight or Blindsight?

Question

Mind Blank as listed would for sure stop the Truesight spell, because it is a divination spell and per the phb pg 259- 260

one willing creature you touch is immune to [..], Divination Spells

but the Monster sense of Trusight is not a spell (Divination or otherwise). It is a special sense, per MM pg 8-9

SENSES

[..] Special senses are described below.

[..]

Blindsight

[..]

Tremorsense

and so on...

But the tricky part is that the Mind Blank spell also says

The spell even foils wish spells and spells or effects of similar power used to affect the target's mind or to gain information about the target.

emphasis mine

So, are a monster's special senses "effects of similar power used to affect the target's mind or to gain information about the target"?

This becomes a big question when players start using Mind Blank in conjunction with Greater Invisibility.

Answer 1

A very strong reading of the phrase "gain information about the target" could apply to using Light and regular vision. That seems silly.

I think it's pretty clear that this should protect from effects that mimic mind reading or other divination, but wouldn't block (for example) a bat's sonar.

If the monster in question has the ability to locate you in the dark by feeling your thoughts, Mind Blank would keep you safe. But if it can locate you because it can feel vibrations or hear your exact location or even has magical eyes that work by something other than perceiving your mind, no.

Answer 2

So, are a monster's special senses "effects of similar power used to affect the target's mind or to gain information about the target"?

No. A monster's senses, even the special ones are not used to affect the target's mind.

Also, gaining information on the target means information beyond what could be possibly be perceived by the normal senses of the creature (yes, including the superhuman ones).

The spells that create a magical sensor, like clairvoyance or clairaudience can be countered though.