I recall reading somewhere or being told to look upon a clearance as a contract. There are two parties to a contract and each has to EXPLICITLY acknowledged their acceptance of the contract.
In other words G- is Cleared to enter controlled airspace etc, and the acceptance of the contract, G- is cleared to etc.
Nothing else will do, because this avoids any doubt about whether a specific contract has been agreed to enter controlled airspace.
I have tried "G- wishes to route X to X, request zone transit through controlled airspace" and the reply "G- is cleared to route towards X, not above 1,500 feet". There is clearly doubt whether a clearance has been given, whatever might be intended. Why not ensure the position is clear - "Is G- cleared to enter controlled airspace .. .. .."
It seems to me simple, be clear whatever words you use, that a contract been EXPLICITLY AND UNEQUIVOCALLY reached between the two parties for you to enter controlled airspace.