SDAM spec defines topology description in https://github.com/mongodb/specifications/blob/master/source/server-discovery-and-monitoring/server-discovery-and-monitoring.rst#topologydescription. This definition contains a list of fields that must be included in topology description, and notably does not include server descriptions or server addresses.

SDAM Monitoring spec in https://github.com/mongodb/specifications/blob/master/source/server-discovery-and-monitoring/server-discovery-and-monitoring-monitoring.rst#events specifies that topology description changed event must be published when:

> When the old topology description is not equal to the new topology description.

At the same time, sdam monitoring spec tests such as https://github.com/mongodb/specifications/blob/master/source/server-discovery-and-monitoring/tests/monitoring/replica_set_with_no_primary.yml#L25 require that a topology description event is published when none of the fields enumerated in the topology description definition change.

It appears that the monitoring spec tests contradict the language in the sdam/monitoring specifications.