Exchange Calendar MCP has clear, action-oriented tool names (list_appointments, create_appointment, delete_appointment) and reasonable descriptions (avg ~120 chars). All 7 tools have input schemas with type definitions and parameter descriptions. However, output schemas are undocumented (tools return plain strings, not structured objects), error handling lacks recovery guidance, and parameter constraints are described in text rather than enforced via enums or JSON Schema patterns. The server is read-only by default with optional write tools, which is good security practice, but destructive operations (delete_appointment) lack confirmation/dry-run patterns. Parameter descriptions are adequate but could be more prescriptive about formats and constraints.

• Document output schemas for all tools. Instead of returning plain strings, return structured JSON with fields like {appointments: [{id, title, start, end, location, organizer}], total_count, next_cursor}. This enables LLMs to extract and chain data.
• Add JSON Schema constraints to parameters: maxLength/minLength for strings, maximum/minimum for integers, pattern for datetime formats. Replace 'YYYY-MM-DD HH:MM format' with a regex pattern in the schema.
• Implement a confirmation pattern for delete_appointment: add a 'confirm' boolean parameter (default false) or a separate 'confirm_delete_appointment' tool that requires explicit confirmation before deletion.
• Enhance error messages with recovery guidance. E.g., 'Invalid date format: got "2024-13-45". Use YYYY-MM-DD (e.g., 2024-01-15).' or 'Appointment not found. Call list_appointments() to see available IDs.'
• Add pagination to list_appointments: include limit (default 20, max 100) and offset/cursor parameters. Return {appointments: [...], total_count, has_more, next_offset} to enable multi-page queries.