Only invoke toolcall with valid JSON

Author: bandoti

examples/main/main.cpp

@@ -5,6 +5,7 @@
 #include "sampling.h"
 #include "llama.h"
 #include "chat.h"
+#include <json.hpp>
 
 #include <cstdio>
 #include <cstring>
@@ -126,12 +127,17 @@ class chat_formatter {
         LOG_DBG("formatted: '%s'\n", formatted.c_str());
 
 #ifdef LLAMA_USE_TOOLCALL
-        if (params_.use_jinja) {
+        if (params_.use_jinja && use_toolcalls) {
             common_chat_grammar_to_sampler(&cparams, vocab_, &params_.sampling);
             if (tc_handler_ != nullptr) {
-                std::string response;
-                tc_handler_->call(formatted, response);
-                return std::string(response);
+                if (nlohmann::json::accept(formatted)) {   // May need a better way to ensure
+                    std::string response;                  // this is intended for a tool-call.
+                    tc_handler_->call(formatted, response);
+                    return std::string(response);
+
+                } else {
+                    return formatted;
+                }
             }
         }
 #endif

toolcall/handler.cpp

@@ -134,30 +134,29 @@ void toolcall::mcp_impl::initialize() {
 static std::string tools_list_to_oai_json(const mcp::tools_list & tools) {
     json tool_list = json::array();
     for (const auto & tool : tools) {
-        json props;
+        json t = json::object();
+
+        t["type"] = "function";
+        t["function"]["name"] = tool.tool_name;
+        t["function"]["description"] = tool.tool_description;
+
+        json props = json::object();
         for (const auto & param : tool.params) {
             props[param.name]["type"] = param.type;
             props[param.name]["description"] = param.description;
         }
+        t["function"]["parameters"]["type"] = "object";
+        t["function"]["parameters"]["properties"] = props;
+
         json required = json::array();
         for (const auto & name : tool.required_params) {
             required.push_back(name);
         }
-        tool_list.push_back({
-                {"type", "function"},
-                {"function", {
-                        {"name", tool.tool_name},
-                        {"description", tool.tool_description},
-                        {"parameters", {
-                                {"type", "object"},
-                                {"properties", props}
-                            }
-                        },
-                        {"required", required}
-                    }
-                }
-            });
+        t["function"]["required"] = required;
+
+        tool_list.push_back(t);
     }
+
     return tool_list.dump(-1);
 }