The metric "VMware Aria Operations Generated | Availability" is generated for all objects in Aria operations. See below;
In this case, the object is not available, except for two points in time where it is in either an error state, or available.
Aria Operations 8.x
There are 3 possible values for this metric;
If an object is in a '-1' or '0' state, it indicates that there is an issue with either availability or collection of the object.