The Gnus Agent doesn't seem to work like most other offline newsreaders. Here are some common questions that some imaginary people may ask:
gnus-agent-fetch-selected-article to
gnus-select-article-hook.No, unless gnus-agent-cache
is nil.
In short, when Gnus is unplugged, it only looks into the locally stored articles; when it's plugged, it talks to your ISP and may also use the locally stored articles.