docs: update Box example config and add token expiry note

Author: matthewhand

README.md

@@ -585,8 +585,9 @@ You can integrate the Box Platform API using your own developer token for authen
 
 #### Example config: `examples/box-claude_desktop_config.json`
 ```json
-{
+"env": {
   "OPENAPI_SPEC_URL": "https://raw.githubusercontent.com/APIs-guru/openapi-directory/refs/heads/main/APIs/box.com/2.0.0/openapi.yaml",
+  "TOOL_WHITELIST": "/folders/{folder_id}/items,/files/{file_id},/search,/recent_items",
   "API_KEY": "${BOX_API_KEY}"
 }
 ```
@@ -603,6 +604,8 @@ You can integrate the Box Platform API using your own developer token for authen
 
 You can now use the MCP ecosystem to list and invoke Box API tools. For integration tests, see `tests/integration/test_box_integration.py`.
 
+Note: developer api keys for free tier box users are limited to 60 minutes :(.  
+
 ### WolframAlpha API Example
 
 ![image](https://github.com/user-attachments/assets/6a634d63-5734-4275-8876-6bacb8beabcc)