This server has significant definition quality gaps. All 7 tools have basic descriptions (10-60 chars), but most fall below the 50-200 char baseline for LLM-optimized descriptions. Input schemas are present with type declarations, but parameter descriptions are minimal or missing context. No output schemas are documented. Error handling is generic ('Employee ID not found', 'Book not found') with no recovery guidance. The server mixes two unrelated domains (LeaveManager + LibraryManager) in one server, violating single-responsibility. No tool annotations (readOnlyHint/destructiveHint) despite clear read/write distinctions. Parameter naming is inconsistent: 'leave_dates' vs 'book_id' vs 'user_name' lack type suffixes.

• Expand tool descriptions to 100-150 chars. Example: 'get_leave_balance' → 'Retrieve the remaining leave days for an employee. Call this before apply_leave to check availability. Returns balance as integer.'
• Document output schemas for all tools. E.g., apply_leave should return {success: boolean, message: string, remaining_balance: integer, applied_dates: [string]}.
• Add recovery guidance to error messages. E.g., 'Employee ID E999 not found. Valid IDs: E001 - E025. Or call search_employees(name="John") to find by name.'
• Add tool annotations: mark apply_leave, borrow_book, return_book with destructiveHint=true; mark all get_* tools with readOnlyHint=true.
• Split into two separate MCP servers (LeaveManager and LibraryManager) or rename tools with domain prefixes (leave_get_balance, library_check_availability) to clarify boundaries.