Traits of a good supervisor

What would you guess to be traits of a good supervisor, whether in private enterprise or public service?

Some folks in Woodstock are wondering about this, in view of a recent promotion announcement at the McHenry County Jail.

I'll start the list, and you can add to it.

Knowledge
Leadership skills
Being prepared for each day's work
Punctuality
Honesty
Integrity
Clean work record
No 30-day work suspensions
Diligent
Professional
Highly qualified

Wouldn't you promote the person who scored the highest on such a list of attributes?