When summarizing, write for an ignorant reader.
Don’t assume that your reader has read the thing you’re summarizing. Summarize in a way that a person who hasn’t read it could understand the ideas conveyed in the text.
Even if your intended reader is your professor and your professor has read what you’re summarizing, write so that a reader who hasn’t read it could understand it. You will write better—it will make it clear to your professor what you understand the text to mean.
Don’t:
List the topics the author talks about without explaining what the author said.
Confuse the reader with references they wouldn’t understand