There are no rules set of how a command parameters should be described in the man page and the buil-in help. Each command is described with a bit different syntax which may be confusing.
* variables: "arg" vs. "<arg>",
* possibility of repeating: "<arg> [arg]..." vs. "<arg>..." vs. "<arg> [arg] ... [arg]",
* mutually exclusive parameters: "[arg | arg]" vs. "[arg] | [arg]",
* and so on.
After evaluating this issue, there are no plans to address it further or fix it in an upcoming release. Therefore, it is being closed. If plans change such that this issue will be fixed in an upcoming release, then the bug can be reopened.