Many of the AI scholarly literature search tools include features for summarizing the search results and uploading PDFs to be summarized. These tools do not search literature, but will summarize items like documents and videos:
Adobe Acrobat Pro has a beta AI Assistant rolling out in a phased manner. Temple users have free access to Adobe Creative Cloud programs, see Temple ITS' site licensed software page for details.
Free tier generates a one sentence PDF summaries and allows unlimited "highlight explanations" (rephrasing passages you highlight) and follow up questions.
Creates article summaries in the form of AI-generated flashcards with several sections. Free tier allows creating 3 flashcards per day, web browser extension, and exporting to Word.
AI summarizer and notetaking tool oriented towards writing and content professionals. Free tier offers a limited number of summaries and writing outputs per day. Ask questions of your entire library, but not of individual documents. Includes writing templates for common outputs like social media posts, co-worker communications, and others. Has a browser extension for using on particular webpages.