The server defines 9 read-only tools with proper schemas and descriptions. All tools have input schemas with typed parameters and descriptions. Tool names follow verb_noun conventions (search_contacts, list_messages, get_chat, etc.). Descriptions are present and explain purpose, though most are brief (50-100 chars). The primary limitation: no output schemas are documented anywhere in the provided source code. Parameter descriptions are adequate but lack detailed constraints, enums, or validation rules. Error handling is not visible in the tool definitions. The security posture is strong (read-only, token auth, Unix socket, whitelist) but this is infrastructure, not reflected in tool definition quality per the rubric.

• Document output schemas for all 9 tools. For each, specify the JSON structure: fields, types, required vs optional. Example for list_chats: {type: 'object', properties: {chats: {type: 'array', items: {type: 'object', properties: {jid: string, name: string, last_message: {type: 'object', ...}, ...}}, total: integer, next_page: integer or null}}.
• Add enum constraints to parameters with fixed sets. For sort_by in list_chats, declare enum: ['last_active', 'name']. For limit, add minimum: 1, maximum: 100 in the schema.
• Enhance parameter descriptions with format and range. E.g., 'JID of the chat (format: example@g.us or example@s.whatsapp.net)', 'ISO 8601 datetime string, e.g., 2024-01-15T10:30:00Z', 'Page number (0-indexed, default 0)'.
• Add error handling guidance to descriptions. E.g., 'If the chat_jid does not exist, returns error 404 with message: Chat not found. Verify JID format (ends in @g.us for groups, @s.whatsapp.net for direct messages).' This guides LLM recovery.
• Document pagination response structure. Specify that list_messages, list_chats, and get_contact_chats return {items: [...], total: int, page: int, has_more: bool}. This lets agents know when to stop fetching.
• Add include_context parameter description detail. Specify: 'If true, returns surrounding messages in context_before and context_after arrays. If false, omits context.' Current description assumes agent knows the structure.
• Clarify get_direct_chat_by_contact parameter naming to contact_phone_number for unambiguous semantics.