The MLA Handbook addresses annotated bibliographies in section 5.31. The annotated bibliography contains descriptive or evaluative comments about your sources. Each citation should adher to MLA guidelines. Begin your comments immediately following the citation. The title might be 'Annotated Bibliography' or 'Annotated List of Works Cited'.
Your instructor may request an annotated bibliography in order to evaluate the types of sources you are selecting for your research. The annotations should show that you have carefully conducted your research and critically analyzed the information you will use to write your paper. The good news is that the 'Works Cited' list will be almost complete before you begin writing. Below is an example of an annotated citation.