A good update reduces the amount another person has to keep wondering about.

The test of an update is not its length but how many open questions it closes. Some reports are full of activity and still leave the reader wondering about the only thing they needed: whether it will be ready, whether to worry, what to tell the person who asked them.

Before sending your next one, write down what the other person is actually wondering and answer that in the first two lines. Detail can follow underneath for anyone who wants it.