No, it can only access the tab you are currently on. And that too just the content that is already available. It can't scroll up and down to load more. It can't follow links. It can't run any actions. You'll get a ton more functionality by just taking a screenshot of the page yourself and pasting it in ChatGPT/Claude/Gemini.

I'm sure that kind of functionality is coming. There's a lot of activity in the chromium repo (chrome/browser/actor/tools) that appears to be adding support for that sort of orchestration.