Copilot for Microsoft 365 AMA: Engage with Experts Live on January 17th

I have observed that copilot does not read all content from sharepoint page. is there a limit to this. I would like to use copilot and asks questions. I already have information on sharepoint pages. can someone please share more insights, is there a limit on how much information copliot can index on sharepoint pages ? document libraries files etc ?