This skill should be used when the user asks to design, audit, or harden Claude Platform Files API upload/reference/lifecycle flows or PDF document requests using file_id, URL, or base64 document sources. Use it for file metadata, deletion, conditional downloadability, PDF request limits, MIME-to-content-block contracts, and source/platform compatibility. Do not use it for text-editor operations, fetching web pages, generic object storage, document authoring, or arbitrary binary processing.