The server defines 12 tools with reasonable naming conventions (all verb-noun style: search_contacts, list_messages, send_message, etc.). Input schemas are present and mostly well-formed with type declarations. However, descriptions are consistently brief and lack LLM-optimization guidance. Output schemas are not documented, the code does not show what fields are returned. Error handling is absent from visible code. Tool composition is reasonable (read operations separate from writes), but several tools lack actionable parameter guidance. The server uses HTTP transport with FastAPI, which is production-ready, but the actual tool implementations are imported from a 'whatsapp' module not shown in source, making verification of output structure and error handling impossible.

• Document output schemas for all 12 tools. Example for search_contacts: 'Returns {contacts: [{jid: string, name: string, phone: string}], total: int}'. Ensure each response includes IDs needed by downstream tools.
• Expand tool descriptions to 80-150 chars. Add context: 'Search for WhatsApp contacts by name or phone. Use this to find a contact JID before calling send_message or get_contact_chats. Returns name, JID, and phone number.'
• Add enum constraints to 'sort_by' parameter in list_chats: declare it as enum['last_active', 'name'] rather than free string.
• Add bounds to numeric parameters: limit (1-100, default 20), page (0+), before/after (1-20, default 5).
• Add format hints to JID and phone parameters: 'JID format: 123456789@s.whatsapp.net (direct) or 123456789@g.us (group)'. 'Phone format: country code + digits, no +, e.g., 14155552671'.
• Implement permission checks for send_* and download_media tools. Log all destructive/sensitive calls with timestamp, user, target, and result.
• Add dry-run support to send_message, send_file, send_audio_message. Example: new parameter 'dry_run: bool (default false)' that validates syntax but does not actually send.
• Document retryability in error responses. Example: 'Contact not found. This is user-fixable, try search_contacts() with a partial name or verify the phone number format.'
• Implement structured error responses with code, message, and recovery suggestion. Example: '{code: 'CONTACT_NOT_FOUND', message: 'JID not found', suggestion: 'Call search_contacts() first'}'.