Houdini attributes have metadata [www.sidefx.com] that decide how they're affected by transformation.

My question is how to know which attribute is which type without printing the metadata from VEX? Like in Geometry Spreadsheet or somewhere else in the UI?

(By "type" I'm not talking about float, vector, etc. I mean the metadata type, like color, normal, etc)

look at MMB Info Window, all of the types are listed there next to the attribute names where applicable

like next to P Pos
next to N Norm
next to v Vec
next to orient Quat
...