Three tools with basic schemas and descriptions, but significant gaps in parameter documentation and output schema clarity. search_catalog and get_product have minimal descriptions (under 100 chars). buy_product description is verbose but lacks clarity on the two-phase flow and parameter interdependencies. No parameter descriptions visible in the schema definitions, only type and name. Output schemas are not documented. Error handling guidance is absent.

• Add explicit parameter descriptions to all three tools. For search_catalog: 'query' → 'Search term to find products (e.g., "steam", "razer")'; 'limit' → 'Maximum results to return (1-100, default 20)'. For buy_product: clarify that order_id and payment_payload are only required on the second call (payment settlement phase).
• Document output schemas for each tool. E.g., search_catalog returns [{product_id, name, price, denominations}]; get_product returns {product_id, name, description, denominations: [{item_id, amount, currency}]}; buy_product returns {order_id, x402_payment_required} on phase 1, {delivery, status_url} on phase 2.
• Add parameter constraints and enums. product_type should be an enum: ['giftcard', 'topup', 'esim', 'phone_rental']. Numeric params (limit, quantity, product_id, item_id) should have min/max bounds.
• Expand buy_product description to explicitly document the two-phase flow: 'Phase 1 (quote): call with email, product_type, product_id, item_id, quantity. Returns order_id and x402 payment requirements. Phase 2 (settle): call again with same order_id plus signed payment_payload. Returns delivery details or status_url.'
• Add error handling guidance. Document that 402 responses are expected (not errors) and guide the agent to sign the x402 requirements and retry. Document what 400, 401, 403, 500 mean and whether they are retryable.