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() < 3 || request.params.size() > 6)
        throw std::runtime_error(
            "sendfrom \"fromaccount\" \"toaddress\" amount ( minconf \"comment\" \"comment_to\" )\n"
            "\nDEPRECATED (use sendtoaddress). Sent an amount from an account to a bitcoin address."
            + HelpRequiringPassphrase(pwallet) + "\n"
            "\nArguments:\n"
            "1. \"fromaccount\"       (string, required) The name of the account to send funds from. May be the default account using \"\".\n"
            "                       Specifying an account does not influence coin selection, but it does associate the newly created\n"
            "                       transaction with the account, so the account's balance computation and transaction history can reflect\n"
            "                       the spend.\n"
            "2. \"toaddress\"         (string, required) The bitcoin address to send funds to.\n"
            "3. amount                (numeric or string, required) The amount in " + CURRENCY_UNIT + " (transaction fee is added on top).\n"