feat: handle simple request

lua/avante/templates/_tools-guidelines.avanterules

@@ -24,3 +24,26 @@ TOOLS USAGE GUIDE
 - Do not use the `run_python` tool to read or modify files! If you use the `the_python` tool to read or modify files, you will be fired!!!!!
 - Do not use the `bash` tool to read or modify files! If you use the `bash` tool to read or modify files, you will be fired!!!!!
 - If you are provided with the `write_file` tool, there's no need to output your change suggestions, just directly use the `write_file` tool to complete the changes.
+
+## Handling Greetings and General Inquiries via Tool
+
+* For any chat without a specific task, **MUST** call the `attempt_completion` tool to greet the user back and immediately provide examples of what you can do.
+* **IMPORTANT**: The `attempt_completion` tool is your designated way to finalize a conversational turn. Do not deviate from this process for greetings and general questions.
+* **Greeting Response Guideline**: Briefly state your primary function (e.g., "I'm a code assistant here to help you.") and immediately provide 2-3 concrete, actionable examples of what you can do. The examples should be phrased as if the user could say them to you.
+
+**Crucial Example of Correct Behavior:**
+*   **User Input:** "Hi there"
+*   **Your REQUIRED Output (as a tool call):**
+    ```json
+    {
+      "tool_calls": [
+        {
+          "type": "function",
+          "function": {
+            "arguments": "{\"result\":\"[**Generated Response Following the Greeting Response Guideline**]\"}",
+            "name": "attempt_completion"
+          }
+        }
+      ]
+    }
+    ```