One cool feature of Zotero is the ability to generate annotated bibliographies from your citations. To do this, you'll first need to download a citation style that accommodates annotations. Go to the Styles repository (linked in the image) and search for "annotated."
Currently, there are only two styles for annotations: an APA style and a Chicago style (which is note, not author-date).
To generate an APA annotated bibliography, click the "Document Preferences" button in the Zotero tab of Microsoft Word and select "American Psychological Association 6th Edition (annotated bibliography with abstract)."
For the references you use in the bibliography, place your annotation in the "Abstract" field in the reference info in the desktop application. After you have added all your citations to you document, click "Add/Edit Bibliography" and the bibliography will be generated with your annotations.
To generate an annotated bibliography using Chicago, go to the "Zotero" tab in Microsoft Word and set your "Document Preferences" to "Chicago Manual of Style 17th edition (note, annotated bibliography)."
To generate an annotated bibliography in Chicago, you'll need to place your annotations in the "Extra" field in the reference record. Then, after you have added all your citations, click "Add/Edit Bibliography" and it will create you bibliography with your annotations.