In Agents, “Event Restrictions” give us more control on what type of transactions agent should be triggered and also perform some pre- transaction commit validations(if required) on inbound XML transactions.
We can access this by clicking the “i” icon as show below:
You will see below options:

Source: You select this value based on below requirements(Order Release examples discussed)
INTEGRATION: If you are receiving Order Release transaction from an external system via GlogXML element and if you want your Agent logic to trigger only for this type of transactions, you select ‘INTEGRATION’ as the source. Only Order Releases uploaded to OTM via XMLs will trigger this agent.