Update 45_Creating_a_Multi_Agent_System.ipynb (#404)

* Update 45_Creating_a_Multi_Agent_System.ipynb

* Update 45_Creating_a_Multi_Agent_System.ipynb

* Update 45_Creating_a_Multi_Agent_System.ipynb

Author: sjrl

tutorials/45_Creating_a_Multi_Agent_System.ipynb

@@ -719,11 +719,13 @@
     "    component=research_agent,\n",
     "    description=\"Use this tool to find information on web or specifically on wikipedia\",\n",
     "    name=\"research_tool\",\n",
+    "    outputs_to_string={\"source\": \"last_message\"},\n",
     ")\n",
     "writer_tool = ComponentTool(\n",
     "    component=writer_agent,\n",
     "    description=\"Use this tool to write content into document store or Notion\",\n",
     "    name=\"writer_tool\",\n",
+    "    outputs_to_string={\"source\": \"last_message\"},\n",
     ")\n",
     "\n",
     "main_agent = Agent(\n",