It is hard to see the justification for making the name of an Agreement optional.
An Agreement is in effect a contract between provider and consumer. Accounting, auditing and logging will be necessary 
for commercial and regulatory reasons.

Any service layer interaction between consumer and provider will be in the context of a specific agreement and there 
should be some unambiguous way of identifying which agreement is relevant.

The Name element would be an easy way to achieve this. An alternative would be to use some combination of information 
from the Context element which may make implementations more complicated than they need to be.