Why call to tell someone something they must have already known?

He was in a meeting when I called to tell him what happened.

He had decided to go ahead on his own, then, and call to tell her where to meet him.

And a couple of weeks later, my dad called to tell me something else.

So down the house would come, my mother called to tell me, in three weeks' time.

Yes, it was one of the things which I had called to tell you.

It is he who called upon me to tell you my story.

She also calls David to tell him it's over once and for all.

They never called back to tell me how big it was going to be.

During the meeting Mary was called on to tell about her work.