I have noticed that SSA 7.2 course, Introduction to creating agents for background processing (chapter Creating agents for background processing, slide 1), says that DB Trace can be used to trace and troubleshoot agents. In a next slides the chapter shows how Tracer (which is definitely not DB tracer) can be used to trace the agents. I am almost sure it is just inaccuracies or typos, but what if not? What if they have the same in the exam?
DB Trace is used for tracing DB "activities", and Tracer is used for tracing activity rules. Agents run activities so you can use Tracer to trace an agent. These activities that Agents run can sometimes perform database transactions, so DB Trace can also be used for such agents.