The server demonstrates solid tool definition practices with complete schemas, consistent naming conventions, and clear descriptions for most tools. All 9 tools are properly registered with Zod schemas and input validation. Naming follows verb_noun patterns (list_entries, add_entry, update_entry, delete_entry, register_user, revoke_user, get_profile, update_profile, get_profile_history). Descriptions range from 42-89 chars, generally adequate but somewhat brief. A primary weakness is the absence of output schema documentation, while input schemas are explicit via Zod, no tool documents what fields agents should expect in responses. Additionally, admin-gated tools (register_user, revoke_user) lack clear permission-checking documentation in descriptions, and error handling recovery guidance is absent from descriptions.

• Document output schemas for all tools. Include example responses and field descriptions. E.g., 'Returns {entry_id: string, food_name: string, calories: number, protein_g: number, carbs_g: number, fat_g: number, meal_type: string, created_at: string (ISO 8601), user_id: string}'.
• Expand register_user and revoke_user descriptions to explicitly state permission requirements and error cases. E.g., 'Register a new user (admin only). Fails with 403 Forbidden if caller is not admin. Returns the new user_id on success.'
• Add recovery guidance to error-prone tools. E.g., delete_entry: 'Permanently deletes an entry. If entry_id is unknown, call list_entries to find it first. This action cannot be undone.'
• Clarify mutually exclusive parameters in get_profile_history. Document: 'Pass either date (single day) OR start_date + end_date (range). Using both causes an error.'
• Expand add_entry and update_entry descriptions to mention nutritional defaults and validation. E.g., 'If protein_g, carbs_g, fat_g are omitted, they default to 0. Calories must be >= 0.'
• Add tool annotation hints (readOnlyHint, destructiveHint, idempotentHint) to signal tool safety to agents. delete_entry should be marked destructive; list_entries and get_profile should be marked read-only.
• Document what fields are required in update_entry responses to support downstream chaining. If agent calls update_entry then list_entries, ensure update_entry returns entry_id so it can be used in further queries.