Hello Popleys,
How about exporting the service into a file (XML formatted) by "Export Policy" in the Policy Manager and extracting "EncapsulatedAssertionReference" elements from it?
You can find the name of the encapsulated assertion in the "Name" sub-element.
Here's an example:
<EncapsulatedAssertionReference RefType="com.l7tech.console.policy.exporter.EncapsulatedAssertionReference">
<Name>API XSS Protection</Name>
<Guid>2be8eaf2-9b42-4173-ace9-3fdb471fb407</Guid>
</EncapsulatedAssertionReference>
I hope it works for your purpose.
Best regards,
Seiji