At a minimum, help text should note this. This is true for things like addwitnessaddress especially.
"\nResult:\n"
            "{\n"
            "  \"txid\":    \"value\",   (string)  The id of the new transaction\n"
            "  \"origfee\":  n,         (numeric) Fee of the replaced transaction\n"
            "  \"fee\":      n,         (numeric) Fee of the new transaction\n"
            "  \"errors\":  [ str... ] (json array of strings) Errors encountered during processing (may be empty)\n"
            "}\n"
            "\nExamples:\n"
            "\nBump the fee, get the new transaction\'s txid\n" +
            HelpExampleCli("bumpfee", "<txid>"));
    }
    RPCTypeCheck(request.params, {UniValue::VSTR, UniValue::VOBJ});
    uint256 hash;
    hash.SetHex(request.params[0].get_str());
    
    CAmount totalFee = 0;
    CCoinControl coin_control;
    coin_control.signalRbf = true;
    if (!request.params[1].isNull()) {
        UniValue options = request.params[1];
        RPCTypeCheckObj(options,
            {
                {"confTarget", UniValueType(UniValue::VNUM)},
                {"totalFee", UniValueType(UniValue::VNUM)},
                {"replaceable", UniValueType(UniValue::VBOOL)},
                {"estimate_mode", UniValueType(UniValue::VSTR)},
            },
            true, true);
        if (options.exists("confTarget") && options.exists("totalFee")) {
            throw JSONRPCError(RPC_INVALID_PARAMETER, "confTarget and totalFee options should not both be set. Please provide either a confirmation target for fee estimation or an explicit total fee for the transaction.");