describe (someone or something) as (something)
To make a descriptive statement about someone or something. Anyone who describes you as "shy" must not know you very well, chatterbox! I wouldn't describe the car as "new" per se—but don't worry, it's in very good condition.
describe (someone or something) to (someone)
To make a descriptive statement about someone or something to someone else. If you describe Bill to me, I might remember him. Can you describe the situation to me? I'm not sure what is going on.
describe someone or something as something
to describe or portray a person or a thing as something or as being in some particular state. Would you describe her as a woman of average height? We described the building as a collection of contemporary architectural clichés.
describe someone or something to someone
to characterize or portray a particular person or thing to someone. Will you describe her to me, please? Please describe yourself to me so I will know you.