Critical gaps across all dimensions. The single tool 'createDeck' has a valid input schema but lacks parameter descriptions entirely. The tool description is minimal (5 words, 31 chars), below the 20-char hard floor for scoring. Storage layer is entirely unimplemented (all methods throw 'Not implemented'). No output schema documented. No error handling guidance. Tool implementation in src/tools/index.ts is a stub that only registers the tool definition but has no actual call handler. This is a skeleton project, not production-ready.

• Expand tool description to 50-150 characters explaining WHAT it does, WHEN to use it, and WHAT it returns. Example: 'Create a new flashcard deck with a name and optional description. Returns the deck ID, creation timestamp, and deck object. Use this before adding cards.'
• Add descriptions to all input parameters. For 'name': 'The deck name (1-100 characters, required). Must be unique within your account.' For 'description': 'Optional deck description (0-500 characters). Summarize the deck topic or purpose.'
• Document the output schema in the tool definition. Specify that createDeck returns: {deck_id: string, name: string, description?: string, createdAt: ISO8601 string, updatedAt: ISO8601 string}.
• Implement the 'tools/call' request handler in src/tools/index.ts to actually invoke storage.createDeck() and return the result. Currently the tool is registered but not callable.
• Add error handling: validate name length (1-100 chars), check for duplicate deck names, and return actionable errors like 'Deck name already exists. Try a different name or use updateDeck() to modify the existing deck.'