**### Problem** The function `_get_dataset_description` caches the dataset description (`description.xml`) to disk, but the cache is never invalidated. Dataset descriptions contain metadata such as dataset status (`active`, `deactivated`, etc.), which may change over time on the OpenML server. Because the cached description file is reused indefinitely, users may receive stale metadata if the local cache is old. There is also a TODO comment in the code suggesting that this cache should invalidate itself after some time. ### Expected Behavior Cached dataset descriptions should be refreshed periodically to ensure that metadata reflects the current state on the server. ### Current Behavior Once `description.xml` is downloaded and cached, it is reused indefinitely unless the cache directory is manually deleted or `force_refresh_cache=True` is used.