If a towered airport operating nothing more than an Aerodrome Information Service
1) It's either "TOWER" or "INFO" - it can't be both. You need to differentiate between the two before you get an accurate answer.
Does the "instruction" have to be complied with at all?
2) This from
CAP410 - Manual of Flight Information Services, Aerodrome: (Section 1, Chapter 7 is the required reading):
Any requests
for position reports downwind, final etc., for the purposes of passing traffic information, only have the status of a request although it is expected that most pilots will comply.
If the airfield is 'INFO' that should answer your question. If the airfield is 'TOWER' and you're asked to do so you
will do it - it's an instruction, otherwise you may find yourself being sent around because you've called final when you weren't expected to. (This is becoming more of a problem at airfields with large 'noise-abatement' circuits, especially if you can't see the whole circuit from the tower).