Identify the target server, auth source, and scope of change. Do not assume a default server URL or admin token; ask for missing credentials instead of searching broadly.
For read-only checks, use the Jellyfin API or available MCP tools to inspect server info, libraries, users, active sessions, scheduled tasks, devices, and logs.
For library or metadata problems, collect the library id/name, affected item ids, provider ids, scan/task status, and recent Jellyfin log lines before recommending refreshes or metadata edits.
For playback or transcoding problems, gather client, stream type, codec, container, bitrate, subtitle mode, hardware acceleration settings, and the relevant transcode/log output.
For user/account work, confirm the exact user and requested permission change before applying writes.

API Notes

Common REST roots are /System/Info, /Users, /Sessions, /Library/VirtualFolders, /Items, /ScheduledTasks, and /Devices.
Jellyfin typically accepts API keys through X-Emby-Token or Authorization: MediaBrowser Token="<token>" depending on the client path.
Treat delete, metadata rewrite, library rescan, and user-permission changes as writes. Summarize the intended object ids before executing them.

Operational Checks

If Jellyfin is containerized, inspect the container status, mounted config and media paths, network reachability, and recent logs before changing settings.
For database, plugin, or upgrade issues, back up or identify the Jellyfin config/data path first.
When no MCP or authenticated API path is available, provide the exact API or admin-console action the user can run rather than inventing a local command.