this is really easy: define goal, context and measurement. assign to dev. discuss with dev if needed. check and collect on ready.

if he is a good developer this is enough for him.

And for you? you are delegating, you have nothing to do about that fking task. except answering questions and collecting results.

Forget it. And if it comes back to your mind forget it again. Until the dev comes to you with a question or with a result.