write more better

Signed-off-by: Michael Crenshaw <350466+crenshaw-dev@users.noreply.github.com>

docs/operator-manual/health.md

@@ -174,25 +174,32 @@ The [PR#1139](https://github.com/argoproj/argo-cd/pull/1139) is an example of Ce
 
 Please note that bundled health checks with wildcards are not supported.
 
-## Health Check Inheritance Rules
+## Health Checks
 
-An Argo CD App's health is inferred from the health of its immediate child resources. In other words, it is inherited
-from the health of the resources which are represented in the App's source.
+An Argo CD App's health is inferred from the health of its immediate child resources (the resources represented in 
+source control). 
 
-The health of a child resource's children may or may not affect the health of the child resource. For example, an 
-unhealthy Pod might not mean that the parent Deployment is unhealthy.
+But the health of a resource is not inherited from child resources - it is calculated using only information about the 
+resource itself. A resource's status field may or may not contain information about the health of a child resource, and 
+the resource's health check may or may not take that information into account.
+
+The lack of inheritance is by design. A resource's health can't be inferred from its children because the health of a
+child resource may not be relevant to the health of the parent resource. For example, a Deployment's health is not
+necessarily affected by the health of its Pods. 
 
 ```
 App (healthy)
 └── Deployment (healthy)
+    └── ReplicaSet (healthy)
+        └── Pod (healthy)
     └── ReplicaSet (unhealthy)
         └── Pod (unhealthy)
 ```
 
-If you want the health of a child-of-a-child resource to affect the health of the child resource, you can write a 
-custom health check for the child resource. The key prerequisite is that the health check must be for an immediate child
-of the app. A custom health check for the child-of-a-child resource will not be enough to cause the app to be marked
-unhealthy.
+If you want the health of a child resource to affect the health of its parent, you need to configure the parent's health
+check to take the child's health into account. Since only the parent resource's state is available to the health check,
+the parent resource's controller needs to make the child resource's health available in the parent resource's status 
+field.
 
 ```
 App (healthy)