Strong foundation with clear verb-noun naming, complete input schemas with proper types and descriptions, and explicit error handling via InvalidArgumentException mapping. Tool descriptions are concise (10-20 chars) but lack context on WHEN to use each tool and dependencies between them (e.g., create_cart must precede add_to_cart). Output schemas are not documented in the visible code. All 6 tools follow consistent patterns and include proper parameter validation. Risk annotations (WRITE, READ_ONLY, DESTRUCTIVE) are present but not formally exposed in the schema.

• Expand tool descriptions to 50-200 characters. Include WHEN to use each tool and dependencies: 'Create a guest cart. Call this first before adding items. Returns a masked cart_id for subsequent operations.'
• Document output schemas for all tools. Example for create_cart: 'Returns {cart_id: string (masked), created_at: ISO 8601 timestamp}'. This enables LLMs to chain tools correctly.
• Implement and expose toolAnnotations methods (getReadOnlyHint(), getDestructiveHint(), getIdempotentHint()) in each tool class so the MCP server can advertise risk levels in the tools/list response.
• Enhance error messages with recovery guidance. Instead of 'An internal error occurred...', return 'Cart not found. Ensure you called create_cart() first and the cart_id is valid.' for NoSuchEntityException.
• Add a confirm_place_order tool or a dry_run parameter to place_order to prevent accidental order placement. Agents should review order details before committing.

Inferred effective spec: 2025-06-18+.

• Relies on Logging (deprecated) - log to stderr or use OpenTelemetry