Template:FAQ:Applications 18b

It can't.

The primary purpose of an SNMP agent is to handle requests for information from management applications. In SNMP terminology, it acts as a "command responder".

It may also issue traps to report significant events or conditions ("notification generator"). But responding to such notifications is a significantly different role, and this is handled by a separate application ('snmptrapd'). Note that it is perfectly possible (even normal) for both agent and trap receiver to run on the same host.