you want the same sized screw driver you'd use on connections inside a fused spur
you don't need crimps or anything to terminate resistor or wires* into these PA's (*or iD biscuits)
when put the conductor onto the alarms cable, are you cutting a bare bit of 15mm ish with bit of insulation on the end & giving it a twist ?
if it was going in a pir you'd cut the end & shove it in.... if going around a screw you'd twist it around & cut the excess off when the screw is tight
its pointless looking at the panel readings there only a guide,
if its going to play up due to poor termination, place the system in day & firm the device with the handle of your screwdriver