Update tool_config.json

tool_config.json

@@ -1,6 +1,6 @@
 {
   "description": "This is a tool that creates an image according to a prompt, which is a text description.",
-  "inputs": "{'prompt': {'type': 'text', 'description': \"The image generator prompt. Don't hesitate to add details in the prompt to make the image look better, like 'high-res, photorealistic', etc.\"}}",
+  "inputs": "{'prompt': {'type': 'string', 'description': \"The image generator prompt. Don't hesitate to add details in the prompt to make the image look better, like 'high-res, photorealistic', etc.\"}}",
   "name": "image_generator",
   "output_type": "image",
   "tool_class": "tool.TextToImageTool"