An annotated bibliography usually functions as a way for you as a writer to compile the various sources that pertain to your specific research topic. The format consists of a citation, then an evaluation and analysis of each source in paragraph form.
The above process will inform any topic on which one researches. For Shakespeare's Macbeth, I would urge you to narrow down your focus before you start looking for sources because of the wealth of scholarship produced. However, if you are unsure of your focus, you may also use an annotated bibliography to set the stage for what your research question might be. Typically, one prepares an annotated bibliography before writing a research paper (or any other paper, for that matter) to show the types of sources one might incorporate in an upcoming paper.
If, on the other hand, you already have the eight sources you mentioned, skim these sources and evaluate their main argument(s) and relevance, as well provide a brief analysis. This process will easily fill three (if not four) pages. In this process of evaluation, you might discover that the sources you have compiled are not relevant or interesting, so conducting further research may be necessary.
Also, since it is unclear as to what topic you have chosen with respect to the play, I would urge you to prepare an annotated bibliography to help in narrowing down the scope of your research.
Please see the reference link below for a few examples.