Wallos MCP demonstrates solid fundamentals: all 32 tools have clear verb-noun naming (list_, get_, create_, update_, delete_), comprehensive parameter schemas with type constraints, and consistent descriptions. However, descriptions average ~80 chars (below the 194-char baseline for A+ tools), lack actionable recovery guidance, and several tools omit critical context about prerequisites or when to use them. Output schemas are not explicitly documented in the source. Error handling is present but generic. The server follows good composition patterns (single responsibility per tool, proper chaining via IDs) but falls short of production-grade polish.

• Document output schemas for all tools. For list_subscriptions, specify: returns array of {id, name, price, category_id, payment_method_id, next_payment, ...}. For settings tools, enumerate valid keys and types.
• Expand descriptions to 100-200 chars. Example: 'Delete a subscription by id. This is permanent and cannot be undone. Verify the subscription id with list_subscriptions first. Returns success or error with reason.'
• Add recovery hints to error-prone tools. E.g., create_subscription: 'If category_name is not found and create_missing=false, call list_categories first to see available options.'
• Implement a dry-run or confirmation pattern for destructive tools. Add optional 'confirm=true' parameter or a separate 'preview_delete_subscription' tool that shows what would be deleted.
• Replace generic 'settings' object schemas with explicit field enums. For update_settings, document: {currency_id, language, timezone, ...} with types and constraints.