Most AWS CLI commands come with options either to specify the input parameters directly on the command line, or input them through a JSON file specified by the cli-input-json property. A template for this JSON file can be generated by using the generate-cli-skeleton property option. 

For the create-user-pool sub-command, we used the cli-input-json property, specifying a JSON file created using the generate-cli-skeleton property option. The create-user-pool sub-command has many properties, and some of them have sub-properties. It would be easy (and less error-prone) to get the template generated in the right format.