Why do I have to specify "SMB/CIFS Server" in SMB health monitor?

That is a great suggestion, however some of my monitors were not valid for nodes. Many monitors did not appear in the drop-down list in the GUI, and the CLI gave me this error when trying to add my SMB node-specific monitor to a node:

01070588:7: The requested monitor rule (/Common/AgfaCVwebSMB_VMWEBHLHHE1) can only be applied to pool members.

Googling the 01070588:7 error turns up this post:

https://devcentral.f5.com/questions/the-requested-monitor-rule-xxxx-can-only-be-applied-to-pool-members

This lead me to discover that the "Alias Address" field of the node has to be populated with something other than the wildcard (and probably the port number field too.) I set those in the monitor and now it appears as a valid monitor for a node.

I am continuing to test.