Your APA annotation should tell your reader WHO, WHAT, WHEN, WHERE, WHY, and HOW.
The elements of an analytical/critical annotation.
Who – how can you assess the authors’ authority and expertise? What are their credentials and affiliations?
What – what sort of investigation is reported on here? Is this a review of the literature? An article on original research? A meta-analysis? What are the authors’ conclusions?
When – is this work current? Does that matter? Has much research been done since publication?
Where – where was the article published and where did you find it?
Why – what is the purpose of the investigation (or, what is the authors’ research question)? Why is it useful to you?
How – what was the authors’ methodology? How does this work fit with the literature, and your own work?