"Оverworked and underqualified". What would that mean?

Hello,

In "Vampire Empire" by Clay and Susan Griffits, we can read the following sentences:

The mayor, an overworked and underqualified official, stood wearily. He was marked as a leader only by his conspicuous red sash and spray of flowers on the front of his top hat.

I wonder, what that "underqualified" would mean here? As I can see from the context, this is something about appearance or behavior of the mayor, not about his skills (i.e. "underqualified" does not mean "of low qualification" or "without necessary qualification" here). However, I failed to find any meaning of this word in dictionaries that would suit here.

Can anyone help me to understand this, please?

Thanks in advance