Tool governance
Tool governance matrix
Every MCP tool the gateway exposes, its required scope, tier, authentication, and side effects. Build agent guardrails against this table.
| Tool | Scope | Tier | Auth | Side effect | Description |
|---|---|---|---|---|---|
| search_products | mcp:search | STARTER | ❌ | read | Wildcard product search across merchant catalog. |
| get_product_details | mcp:read | STARTER | ❌ | read | Fetch full product detail by id. |
| browse_categories | mcp:read | STARTER | ❌ | read | List merchant categories and counts. |
| get_merchant_profile | mcp:read | STARTER | ❌ | read | Merchant profile, trust score, capabilities. |
| compare_products | mcp:read | GROWTH | ❌ | read | Side-by-side comparison of multiple products. |
| check_availability | mcp:read | GROWTH | ❌ | read | Live stock availability for a SKU + location. |
| nlweb_ask | mcp:search | GROWTH | ❌ | read | NLWeb natural-language semantic discovery. |
| preview_checkout | mcp:read | GROWTH | ❌ | read+preview | Compute pricing/shipping/tax without committing. |
| apply_discount | mcp:read | GROWTH | ❌ | read+preview | Validate discount code and preview totals. |
| create_cart | mcp:write | GROWTH | ✅ | write | Create a cart resource (no payment). |
| select_shipping_option | mcp:write | GROWTH | ✅ | write | Lock shipping option on a cart. |
| complete_checkout | mcp:checkout | GROWTH | ✅ | write+payment | Places the order for a checkout_session_id. Returns COMPLETED with an order_id, or PENDING_EXTERNAL_CONFIRMATION with the link the buyer must open to approve or pay. |
| ucp_create_checkout | mcp:write | PRO | ✅ | write | UCP unified checkout intent (multi-rail). |
| ucp_complete_checkout | mcp:checkout | PRO | ✅ | write+payment | UCP settle: multi-rail (card / x402 / wallet). |
| ucp_cancel_checkout | mcp:write | PRO | ✅ | write+cancel | Cancel pending UCP checkout intent. |
Side effects: read (no state change) · read+preview (compute, no commit) · write (creates resource) · write+payment (charges money) · write+cancel (releases resource).
Scope semantics: mcp:read (discovery), mcp:search (NLWeb + wildcard), mcp:write (cart mutation), mcp:checkout (settlement).
Tier upgrade path:
View tier comparison →