Start the open UCP purchase flow — no auth needed. Creates a cart session and returns a cart_id (24-hour TTL). Optionally seed with pre-configured blind items and customer details. Next step: update_cart to add items, then create_checkout → complete_checkout to mint the payment link.
| Name | Required | Description | Default |
|---|---|---|---|
| items | No | Optional initial items (configured blinds) | |
| customer | No | Optional customer details |
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations provided, the description carries the full burden. It discloses key behaviors: 'no auth needed', '24-hour TTL', 'returns a cart_id', and optional seeding with items/customer details. It lacks some details like idempotency or side effects but covers the essentials well for a cart creation tool.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.
Is the description appropriately sized, front-loaded, and free of redundancy?
The description is three sentences, front-loaded with purpose, quickly covering TTL, optional inputs, and next steps. Every sentence provides value with no fluff or repetition, making it concise and well-structured.
Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.
Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?
Given two optional parameters and no output schema, the description is remarkably complete. It explains the return value (cart_id), the TTL, the optional inputs, and the subsequent flow steps. This provides enough context for an agent to invoke the tool correctly and understand what happens next.
Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.
Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?
Schema coverage is 100% with clear descriptions for items and customer. The description adds 'Optionally seed' and 'pre-configured blind items', but this mostly restates the schema. It does not provide additional semantic value beyond what the schema already communicates, so the baseline score of 3 is appropriate.
Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.
Does the description clearly state what the tool does and how it differs from similar tools?
The description clearly states the tool's function: 'Start the open UCP purchase flow' and 'Creates a cart session and returns a cart_id'. This distinguishes it from sibling tools like create_checkout or update_cart by explicitly identifying it as the entry point for the purchase flow.
Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.
Does the description explain when to use this tool, when not to, or what alternatives exist?
It provides explicit usage guidance: 'no auth needed' indicates when this is appropriate, and 'Next step: update_cart to add items, then create_checkout → complete_checkout to mint the payment link' gives a clear workflow and context for sequencing relative to other tools. This effectively tells the agent when to use this tool as the starting action.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
Add one secure layer between your agents and this server.
Most tools have clearly distinct purposes, but search_products and lookup_catalog overlap significantly in filtering by category and dimensions, which could confuse an agent. The three search/filter tools have subtle differences described, but the overlap lowers the score from perfect.
All tools use consistent snake_case with verb-noun structure (e.g., cancel_cart, get_product, update_checkout). There is no mixing of conventions, and the verbs clearly indicate the action, making the set predictable and easy to parse.
26 tools is slightly above the typical well-scoped range of 3-15, but the domain of an e-commerce blinds shop with additional services like AR, swatches, and price matches justifies the count. A couple of legacy tools (create_order, submit_enquiry) add minor bloat.
The core purchase flow (search, configure, cart, checkout, payment, order tracking) is fully covered. Additional services like AR visualization, swatches, price match, and WhatsApp handoff are present. Missing features like order listing or coupon application are minor gaps.