Assuming you have your ESXi Host object named "esxHost" in the script, this might be what you are looking for:
System.log("CPU Total Capacity: "+esxHost.parent.summary.effectiveCpu);
System.log("Memory Total Capacity: "+esxHost.parent.summary.effectiveMemory);
Those values come from the Compute Resource that the host is a child of. In the case of a cluster, it is a cluster compute resource and a standalone host it is simply a compute resource - I think 
Hi Burke,
Thanks for your help. This is great, but I steel need this values for a single Host. If you connect vCenter client directly to a host, you can see those numbers. So, how can I reach this values from a host?
I'm attaching a screenshot.
Thanks a lot,
D.
Okay, now you've pointed to different information... This was a bit challenging to figure out too since no project I've ever been involved in got anywhere near this particular object... The "VcClusterHostPowerAction" is a type of VcClusterAction. And that is a property of a cluster recommendation ... so you don't get this information by host - you get it by cluster and it's a bit complicated because it is based on a DRS recommendation. I ( and those I asked for assistance from ) don't believe this is what you actually need based on this thread. Instead, you should just be concerned with your host's overhead + memory used. This will get you an approximate value for the "capacity" that the host is adding to a cluster 
This took a bit of digging to figure out.
So for an individual host, it should be approximately:
var memUsage = esxHost.summary.quickStats.overallMemoryUsage;
System.log("Memory Usage: "+memUsage);
var configs = esxHost.systemResources.child;
for each (var child in configs){
if(child.key == "host/system"){
var hostReservation = child.config.memoryAllocation.reservation;
}
}
var hostOverhead = memUsage + hostReservation;
var totalCapacity = esxHost.hardware.memorySize / (1024*1024);
var availableCapacity = totalCapacity - hostOverhead;
System.log("Host Overhead: "+hostOverhead);
System.log("Total Capacity: "+totalCapacity);
System.log("Available Capacity: "+availableCapacity);
In my test cluster, I have 3 hosts - each with 8GB memory the above code properly reflects a single host's memory for the cluster "Capacity" as you are requesting. Obtaining cpu info will be nearly identical as each object I obtained Memory info from also has CPU details.
