fix(docs): update Windows encoding note for LiteLLM to improve clarity

docs/agents/models.md

@@ -315,22 +315,19 @@ layer, providing a standardized, OpenAI-compatible interface to over 100+ LLMs.
         )
         ```
 
-!!!info "Note for Windows users"
+!!!warning "Windows Encoding Note for LiteLLM"
+
+    When using ADK agents with LiteLLM on Windows, you might encounter a `UnicodeDecodeError`. This error occurs because LiteLLM may attempt to read cached files using the default Windows encoding (`cp1252`) instead of UTF-8.
+
+    To prevent this, we recommend setting the `PYTHONUTF8` environment variable to `1`. This forces Python to use UTF-8 for all file I/O.
 
-    ### Avoiding LiteLLM UnicodeDecodeError on Windows
-    When using ADK agents with LiteLlm on Windows, users might encounter the following error:
-    ```
-    UnicodeDecodeError: 'charmap' codec can't decode byte...
-    ```
-    This issue occurs because `litellm` (used by LiteLlm) reads cached files (e.g., model pricing information) using the default Windows encoding (`cp1252`) instead of UTF-8.
-    Windows users can prevent this issue by setting the `PYTHONUTF8` environment variable to `1`. This forces Python to use UTF-8 globally.
     **Example (PowerShell):**
     ```powershell
-    # Set for current session
+    # Set for the current session
     $env:PYTHONUTF8 = "1"
+
     # Set persistently for the user
     [System.Environment]::SetEnvironmentVariable('PYTHONUTF8', '1', [System.EnvironmentVariableTarget]::User)
-    Applying this setting ensures that Python reads cached files using UTF-8, avoiding the decoding error.
     ```