A good annotation should include summary and analysis of your source.

When deciding what is important enough to include, consider some of the following questions to guide your appraisal:

• What qualifies the author to write on this subject?
• Is the author affiliated with a reputable institution in this field?
• Is the author engaged in research or otherwise considered an expert in this field?
• Is this source current or contemporary to the problem/event being studied?
• Is this the most recent or most critically valued edition (for a book)?
• Is the journal or other publisher reputable?

Once your primary evaluation is complete, you will move on the assessing the content itself. Consider some of these elements as you review each source:

• Who is the intended audience?
• Is the author stating facts or presenting her opinion or interpretation as they were facts?
• What supporting evidence does the author provide?
• Did the author perform the research, or organize and present the research of others?
• If the author used the research of others, are the sources the author cites credible?
• Are there errors or omissions of fact?

Also, consider the particular usefulness of each source:

• Is the information helpful for your particular assignment?
• Does it help answer your research question(s)?
• Is this source different from your other sources, or does it repeat information you already have?
• Is the source providing you with a different perspective on your topic, or changing your beliefs or thinking about your subject?

You don't need to answer all of these questions in every entry; different sources are significant in different ways.

Adapted from A Complete Guide to the MLA Annotated Bibliography. http://www.easybib.com/guides/annotated-bibliographies