diff --git a/src/rpc/abc.cpp b/src/rpc/abc.cpp
--- a/src/rpc/abc.cpp
+++ b/src/rpc/abc.cpp
@@ -14,17 +14,15 @@
 
 static UniValue getexcessiveblock(const Config &config,
                                   const JSONRPCRequest &request) {
-    if (request.fHelp || request.params.size() != 0) {
-        throw std::runtime_error(RPCHelpMan{
-            "getexcessiveblock",
-            "\nReturn the excessive block size.",
-            {},
-            RPCResult{"  excessiveBlockSize (integer) block size in bytes\n"},
-            RPCExamples{HelpExampleCli("getexcessiveblock", "") +
-                        HelpExampleRpc("getexcessiveblock", "")},
-        }
-                                     .ToString());
+    RPCHelpMan{
+        "getexcessiveblock",
+        "\nReturn the excessive block size.",
+        {},
+        RPCResult{"  excessiveBlockSize (integer) block size in bytes\n"},
+        RPCExamples{HelpExampleCli("getexcessiveblock", "") +
+                    HelpExampleRpc("getexcessiveblock", "")},
     }
+        .Check(request);
 
     UniValue ret(UniValue::VOBJ);
     ret.pushKV("excessiveBlockSize", config.GetMaxBlockSize());
@@ -33,23 +31,21 @@
 
 static UniValue setexcessiveblock(Config &config,
                                   const JSONRPCRequest &request) {
-    if (request.fHelp || request.params.size() != 1) {
-        throw std::runtime_error(RPCHelpMan{
-            "setexcessiveblock",
-            "\nSet the excessive block size. Excessive blocks will not be used "
-            "in the active chain or relayed. This discourages the propagation "
-            "of blocks that you consider excessively large.",
-            {
-                {"blockSize", RPCArg::Type::NUM, RPCArg::Optional::NO,
-                 "Excessive block size in bytes.  Must be greater than " +
-                     std::to_string(LEGACY_MAX_BLOCK_SIZE) + "."},
-            },
-            RPCResult{"  blockSize (integer) excessive block size in bytes\n"},
-            RPCExamples{HelpExampleCli("setexcessiveblock", "25000000") +
-                        HelpExampleRpc("setexcessiveblock", "25000000")},
-        }
-                                     .ToString());
+    RPCHelpMan{
+        "setexcessiveblock",
+        "\nSet the excessive block size. Excessive blocks will not be used in "
+        "the active chain or relayed. This discourages the propagation of "
+        "blocks that you consider excessively large.",
+        {
+            {"blockSize", RPCArg::Type::NUM, RPCArg::Optional::NO,
+             "Excessive block size in bytes.  Must be greater than " +
+                 std::to_string(LEGACY_MAX_BLOCK_SIZE) + "."},
+        },
+        RPCResult{"  blockSize (integer) excessive block size in bytes\n"},
+        RPCExamples{HelpExampleCli("setexcessiveblock", "25000000") +
+                    HelpExampleRpc("setexcessiveblock", "25000000")},
     }
+        .Check(request);
 
     if (!request.params[0].isNum()) {
         throw JSONRPCError(
diff --git a/src/rpc/avalanche.cpp b/src/rpc/avalanche.cpp
--- a/src/rpc/avalanche.cpp
+++ b/src/rpc/avalanche.cpp
@@ -13,16 +13,14 @@
 
 static UniValue getavalanchekey(const Config &config,
                                 const JSONRPCRequest &request) {
-    if (request.fHelp || request.params.size() != 0) {
-        throw std::runtime_error(RPCHelpMan{
-            "getavalanchekey",
-            "\nReturns the key used to sign avalanche messages.\n",
-            {},
-            RPCResults{},
-            RPCExamples{HelpExampleRpc("getavalanchekey", "")},
-        }
-                                     .ToString());
+    RPCHelpMan{
+        "getavalanchekey",
+        "\nReturns the key used to sign avalanche messages.\n",
+        {},
+        RPCResults{},
+        RPCExamples{HelpExampleRpc("getavalanchekey", "")},
     }
+        .Check(request);
 
     if (!g_avalanche) {
         throw JSONRPCError(RPC_INTERNAL_ERROR, "Avalanche is not initialized");
@@ -33,21 +31,19 @@
 
 static UniValue addavalanchepeer(const Config &config,
                                  const JSONRPCRequest &request) {
-    if (request.fHelp || request.params.size() != 2) {
-        throw std::runtime_error(RPCHelpMan{
-            "addavalanchepeer",
-            "\nAdd a peer to the set of peer to poll for avalanche.\n",
-            {
-                {"nodeid", RPCArg::Type::NUM, RPCArg::Optional::NO,
-                 "Node to be added to avalanche."},
-                {"publickey", RPCArg::Type::STR_HEX, RPCArg::Optional::NO,
-                 "The public key of the node."},
-            },
-            RPCResults{},
-            RPCExamples{HelpExampleRpc("addavalanchepeer", "5")},
-        }
-                                     .ToString());
+    RPCHelpMan{
+        "addavalanchepeer",
+        "\nAdd a peer to the set of peer to poll for avalanche.\n",
+        {
+            {"nodeid", RPCArg::Type::NUM, RPCArg::Optional::NO,
+             "Node to be added to avalanche."},
+            {"publickey", RPCArg::Type::STR_HEX, RPCArg::Optional::NO,
+             "The public key of the node."},
+        },
+        RPCResults{},
+        RPCExamples{HelpExampleRpc("addavalanchepeer", "5")},
     }
+        .Check(request);
 
     if (!g_avalanche) {
         throw JSONRPCError(RPC_INTERNAL_ERROR, "Avalanche is not initialized");