The preference example in appendix 3 defines several ServiceDescriptionTerms like job:numberOfCPUs, job:realMemorySize, 
which are confusing. I doubt if they are better defined as wsag:ServiceProperties instead of ServiceDescriptionTerms.

In Section 4.2.5, job:networkBandwidth and job:numberOfCPUs are used as examples of ServiceProperties, and In Appendix 2
, the ServiceDescriptionTerms are used to define the Job with jsdl:JobDefinition. 

According to the definitions of ServiceDescriptionTerms and ServiceProperties, their distinctions seem to me not very 
clear: ServiceDescriptionTerms define the functionality that will be delivered under an agreement. Service Properties 
are used to define measurable and exposed properties associated with a service such as response time and throughput.