Clarification on Optional taskSets Parameter in ECS DescribeTaskSets API

[ParthaI]

I’m looking for clarification regarding the behavior of the ECS DescribeTaskSets API.

As per the documentation, the taskSets parameter is optional. However, when I attempt to call the API without specifying any task set IDs, I receive the following error:

An error occurred (InvalidParameterException) when calling the DescribeTaskSets operation: TaskSets cannot be empty.

This behavior is also observed when using the AWS CLI. For example:

aws ecs describe-task-sets \
  --cluster arn:aws:ecs:us-east-1:123456789098:cluster/steampipe-test-env2_Batch_d22fbc22-01cd-3f17-9793-3e3ed0d605b2 \
  --service tewst23-service-5nnlo947-task-set

Returns:

An error occurred (InvalidParameterException) when calling the DescribeTaskSets operation: TaskSets cannot be empty.

Given that the taskSets field is marked as optional in the API reference, I expected the API to return all available task sets for the service when the parameter is omitted.

Could you please confirm:

• Is this the expected behavior?
• If so, under what conditions is it valid to omit the taskSets field?
• Is the documentation inaccurate or incomplete regarding this aspect?

Thanks in advance for your guidance!