The rpc help (documentation) is currently manually updated with no checks of correctness or consistency with the code.

I think the goal should be that the rpc help is generated by pretty printing a cpp object (as opposed to the hardcoded string)

In a first step, the constructor of the class could just take the name of the method, and an array of args. Each arg would be a json value (c.f. https://gist.github.com/karel-3d/1490786786525b0365ea8f459a9fc683#examples-1) with the type and the name to be used when calling with named arguments. Also, each arg would have flags for optional/required (and a default for non-required args), as well as a short description string.

Further enhancements would be to do the same for the result (returned json) and finally to check the types provided in the documentation against the types passed during runtime.