At a minimum, help text should note this. This is true for things like addwitnessaddress especially.
{
    CWallet * const pwallet = GetWalletForJSONRPCRequest(request);
    if (!EnsureWalletIsAvailable(pwallet, request.fHelp)) {
        return NullUniValue;
    }
    if (request.fHelp || request.params.size() != 1)
        throw std::runtime_error(
            "getaddressesbyaccount \"account\"\n"
            "\nDEPRECATED. Returns the list of addresses for the given account.\n"
            "\nArguments:\n"
            "1. \"account\"        (string, required) The account name.\n"
            "\nResult:\n"
            "[                     (json array of string)\n"
            "  \"address\"         (string) a bitcoin address associated with the given account\n"
            "  ,...\n"
            "]\n"
            "\nExamples:\n"