Share 'Reviews...Always tell the truth?'

I was recently approached by a book agent to review a book on my blog. I did not like the book, found typos, and the prose was erratic along with some other issues.. I even had someone else read it and they agreed. Rather than post a negative review, I summarized the book. The agent was disappointed but when I told her my negative feelings, she preferred the summary. What are your thoughts? Joyce…