No Gable Vent On Siding
It's always a good idea if possible to install a
gable vent for attic ventilation.
You won't know if a gable vent is necessary here, until you go into the house.
This house could have a cathedral or vaulted ceiling, where it would not require a gable vent, because there's no attic.
If you are inspecting a home that does not have a gable vent installed in an area like this, the roof could have dormer vents to provide proper ventilation.
This is another instance where you do not assume there is a problem, you verify that there is a problem.