Add the possibility of increasing consumed resources

Signed-off-by: Yuki Iwai <yuki.iwai.tz@gmail.com>

keps/sig-apps/3998-job-success-completion-policy/README.md

@@ -223,7 +223,7 @@ we probably can not evaluate the SuccessPolicy correctly.
 
 - If we allow to set unlimited size of the value in `.spec.successPolicy.criteria.succeededIndexes`,
 we have a risk similar to [KEP-3850: Backoff Limits Per Index For Indexed Jobs](https://github.com/kubernetes/enhancements/tree/76dcd4f342cc0388feb085e685d4cc018ebe1dc9/keps/sig-apps/3850-backoff-limits-per-index-for-indexed-jobs#risks-and-mitigations).
-So, we limit the size of `succeededIndexes` to 64Ki.
+So, we limit the size of `succeededIndexes` to 64KiB.
 
 ## Design Details
 
@@ -559,6 +559,9 @@ No.
 
 ###### Will enabling / using this feature result in any new API calls?
 
+Yes, if the Job meets the SuccessPolicy,
+the job-controller must make an additional API call to update the condition with `SuccessCriteriaMet`.
+
 No.
 
 ###### Will enabling / using this feature result in introducing new API types?
@@ -583,7 +586,9 @@ No.
 
 ###### Will enabling / using this feature result in non-negligible increase of resource usage (CPU, RAM, disk, IO, ...) in any components?
 
-No.
+Yes, the job-controller will consume more CPU and memory to compute the set of indexes from the `succeededIndexes`. 
+Especially, if there are many of them (approaching the maximum size of them, 64KiB), 
+the consumed resources might be non-negligible.
 
 ###### Can enabling / using this feature result in resource exhaustion of some node resources (PIDs, sockets, inodes, etc.)?
 
@@ -702,7 +707,7 @@ type SuccessPolicyCriterion struct {
 }
 ```
 
-### Use JobSet instead of Indexes Job
+### Use JobSet instead of Indexed Job
 
 The [JobSet](https://github.com/kubernetes-sigs/jobset) is a custom resource for managing a group of Job as a unit.