Given that this is a VFR flight, in most cases you would be tracking via an approach point as annotated on your VTC, this helps ATC identify where you are and this would also generally correspond to an altitude constraint being the lower limit or below for that airspace. You must remember that all the "W's" need to be accounted for: Who you are, where you are, what you want <intentions> etc.
Even though you have submitted a flight plan ATC has no crystal ball and they may at times require further information from you, for example, in your notes above there is no mention of "where you are" and hence the altitude does not automatically correspond to your location in reference to the airport. I would reference the VTC for Perth before attempting the answer at least as a guide. If you don't have the VTC here is a link:
www.airservicesaustralia.com/aip/current...rt/vtc/Perth_VTC.pdf
Usually when requesting clearance for C class firstly check the ATIS, then call them up in this order:
Callsign, position, intentions, recieved (ATIS Identifier)......blah blah blah.
Example at YBCG inbound from the north:
"Gold Coast TWR Charlie Charlie Charlie,1500ft at Q1, inbound with 'Echo' request airways clearance"
or
"Gold Coast TWR Charlie Charlie Charlie inbound with 'Echo' 1500ft Q1 request clearance"
Typical response:
"Charlie Charlie Charlie, track over water maintain 1500"...etc etc.....
or
"Charlie Charlie Charlie, identified track via Burleigh Heads or direct/Robina Town centre, etc, maintain 1500"
Hope this helps