@EnlightenedOwl in my practice we have a number of GPs (some of whom are GPSIs), nurse practitioners who can prescribe, practice nurses, HCAs, a phlebotomist, an in house pharmacist who sees patients for reviews etc, an in house physio, a part time mental health nurse and a care coordinator.
By simply giving an idea of the nature of the problem the very well trained receptionist can make an appointment with the most appropriate professional. This is not always the GP, but the patient may automatically ask for a GP appointment not knowing that 1, all these other HCPs are available and 2, still being of the mindset that at a GP surgery the only person that can help them is the GP.
21st century primary care is a very different beast now.
The receptionist doesn’t want details, they just want basic info like possible urine infection, skin rash, shoulder pain, needs a sick note, needs a repeat prescription, suspicious lump. They are not making clinical decisions as to assessment or treatment, (or they shouldn't be!) they are allocating appointments appropriately at the GPs request.
The receptionist doesn’t make a decision as to how important the callback is, everyone gets added onto a call list in a linear fashion. However the reason they put in the box allows the clinician to scan though and prioritise their calls - that’s how we work.