I see several issues with
yet another agent
How is the agent deployed to the target system ?
Without a centralized software management system (which needs an agent ...), this means manual install on every client. Not very promising.
Pull or push model ?
With push, the agent needs to open a port and listen to incoming request. Any open port is usually considered a security risk.
Using pull, it must regularly check for management request. One cannot do
immediate requests but wait for the next pull. And with lots of clients, pulls will clutter the network.
How can a client (running the agent) be discovered ?
How should the agent talk to the management application ?
REST would be nice (and maybe the only reason for a new agent).
But this still leaves resource representation open.
XML is considered bloated and not very useful for monitoring. Monitoring must be done on the client (RRDtool ?!) as well as policy evaluation. Policy violations (+disk full !+) can then be reported asynchronously.
How to represent managed entities and their relations ?
It should be object oriented and allow discovery of relations. If a network switch fails, you do want to know which services are affected. The model must support to discover services routed over the failed switch.
Management of clients in case of critical hardware failures
If the power supply burns, the CPU just overheated or the kernel crashed, the system must still be manageable. This requires as Baseboard Management Controller (BMC) ideally speaking the same language as the agent.
Writing management instrumentation is hard. How can existing instrumentation code being reused ?
Mixed Windows/Unix/Linux environments are fact today.
Who's going to develop and support the agent across these environments ?
So what's wrong with existing standards and solutions ? CIM and WS-Management have solved most of the above mentioned problems.
Instead of reinventing the wheel, effort is better spend in making these standards more mature and interoperable. Interestingly enough, Microsoft opted for WS-Management because customer asked them for interoperable management.
OMC should jump onto this bandwagon and push Microsoft further down this road.