It all depends on what the company says in writing or mailer etc.
Some are just checks. Which is usually a 15 or 20 point check.
Which will let you know how its running "as is".
Cleaning condenser, adding freon(if needed) replacing capacitors, etc. costs more if the initial tune up is very low priced for your area. You usually get what you pay for.
New spark plugs, plug wires, fuel filter, air filter, change oil and filter, check all fluid levels, check lights. Oh wait.....that's on vehicles. (I know...I'm a real wisenheimer) An HVAC tune-up consists of.....(should consist of anyways)...
checking air filter, blower motor and wheel, lube any parts that can be lubed,
check airflow, check and clean coils if necessary, check drain, check thermostat, check wiring, check voltages and amperage draws, check refrigerant charge, check temperature split, inspect outdoor fan motor bearings and blade, check capacitors. That's pretty much it for what you have.
Believe none of what you hear and half of what you see.