Some annotations are merely descriptive, summarizing the authors' qualifications, research methods, and arguments. Your professor might also ask you to identify the authors' theoretical frameworks.
Many annotations evaluate the quality of scholarship in a book or article. You might want to consider the logic of authors' arguments, and the quality of their evidence. Your findings can be positive, negative, or mixed.
Your professor might also want you to explain why the source is relevant to your assignment.
***The Online Writing Lab (OWL) has very helpful resources on constructing annotated bibliographies.
This is a good reference chart for how to cite your articles in APA style: https://owl.purdue.edu/owl/research_and_citation/using_research/documents/20180719CitationChart.pdf