Author intent matters in how useful their information can be to your research, depending on which information need you are trying to meet. For instance, when you look for sources that will help you answer a research question or evidence for your answer, you will want the author’s main purpose to be to inform or educate.
This section of the passage stands out to me because it's a great tip to finding reliable information. If the author intent is not to educate you will most likely find opinion-based information. This is good but opinions don't win arguments facts do. If you know the author's intent, you can save time on research.