An annotated bibliography is simply an expanded bibliography. In addition to the citation you provide at the end of your paper or project, you provide a few sentences about the citation and why/how you plan on using it in your assignment.
The annotations in an annotated bibliography are not summaries. It is information you gather from evaluating the source yourself.
The OWL at Purdue provides a simple recipe for an annotation:
See also Cornell University https://guides.library.cornell.edu/annotatedbibliography
Located in Room 107 within the Center for Student Learning in Addlestone Library, Peer consultants in the Writing Lab assist students in the writing process. The current schedule is posted on the Writing Lab website.
This is a four-part series given by Mr. David Taylor from Savannah Technical College on how to write an APA-MLA Annotated Bibliography