Can I post on the Internet a page which summarizes the essential technical contributions of a paywalled article? This is a follow-on to this question.  Suppose I have a collection of research articles, written by other people, and related to a specific topic.  Suppose I want to post on the Internet a page which is a bibliography of those articles together with a link to an elsewhere-posted PDF of the article, when that is available, which could be either free and open or paywalled.  When the article is paywalled or not available on the Internet, I want to post a summary of the essential technical contributions of the article.  The summary would be what I would provided as lecture notes for a class if I read the article for understanding, and then wanted to teach the article to a group of students.  Do you see anything wrong with that?
As long as you write the summary yourself, rather than copying the important sentences, there is no problem. It would be the same as an open newspaper article reporting about some research study.

Don't forget to provide proper citations, but as far as I understand, you are already doing that.