For ease of use, Alibaba Cloud CLI provides online help commands. You can use the help commands to query valid operations supported by Alibaba Cloud products.
For instance, if you want to query all the operations supported by ECS, run
aliyuncli ecs help command and the query result is shown as follows.
If you want to query the parameters of an ECS operation, run
aliyuncli ecs <operation name> help. Taking the DescribeRegions operation as an example, the query result is shown as follows.