MCP Waifu Chat exhibits fundamental definition quality gaps across naming, descriptions, and error handling. While tool names use appropriate verb-noun patterns (create_user, delete_user, get_dialog_json), descriptions are universally minimal and parameter documentation is sparse. All 8 tools have basic schemas with typed parameters, but lack depth in guidance for LLM selection. No input validation rules, error recovery paths, or output schema documentation visible. Security concerns around user management tools without explicit permission checks.

• Expand all tool descriptions to 50 - 200 characters with WHAT, WHEN, and output summary. E.g., 'Creates a new user with a unique ID. Call before chat() or other user-specific operations. Returns user_id and creation timestamp.'
• Add parameter descriptions for all fields. For user_id: 'Unique identifier (string, alphanumeric, 1-64 chars). Will be created on first use or looked up if already exists.' For message in chat: 'The user's input message (plaintext, max 2000 chars). Cannot be empty.'
• Document output schemas in tool descriptions. E.g., 'Returns {user_id: string, created_at: ISO8601, status: string}' or 'Returns dialog array: [{role: string, content: string, timestamp: ISO8601}]'.
• Split get_dialog_json and get_dialog_str into a single get_dialog tool with a format parameter (enum: 'json' | 'string'). Or clearly differentiate: 'get_dialog_json: returns machine-readable JSON for parsing. get_dialog_str: returns formatted plaintext for display.'
• Add confirmation/dry-run to delete_user. Description: 'Permanently deletes user and all associated dialog history. No undo. Confirm with confirm_delete_user(user_id) first.' Or return a one-time confirmation token.
• Add error guidance to every tool. E.g., 'If user not found: call create_user() first. If chat fails with 'dialog limit': reset_dialog() to clear history. If rate limited: wait 60 seconds.'
• Document prerequisites and ordering. E.g., chat and reset_dialog descriptions: 'Requires user to exist. Call create_user(user_id) first if new.'

Inferred effective spec: <=2025-11-25.

• Relies on Logging (deprecated) - log to stderr or use OpenTelemetry