Instead of just saying "User created ticket #4" or "Created ticket #4," the activity text should include which tracker the ticket was created on, e.g. "User created ticket #4 on Support Requests"
What are the trackers? How are they determined?
Tracker is the place where tickets live. For example, this ticket lives in the tracker with a name "Tickets" (you can see it's selected in the top menu).
Tickets are linked to trackers via their app_config_id, which will point to the specific tool configuration.
For the overview what are tools and other pieces in Allura see developer docs