Implement my_custom_tool for square calculation and add to agent

app.py

@@ -58,7 +58,7 @@ with open("prompts.yaml", 'r') as stream:
     
 agent = CodeAgent(
     model=model,
-    tools=[final_answer,my_custom_tool,get_current_time_in_timezone,image_generation_tool] ## add your tools here (don't remove final answer)
+    tools=[final_answer,my_custom_tool,get_current_time_in_timezone,image_generation_tool], ## add your tools here (don't remove final answer)
     max_steps=6,
     verbosity_level=1,
     grammar=None,