4OVER4

Start a 4OVER4 checkout (UCP)

create_checkout

Starts a 4OVER4 checkout for print items, which the buyer finishes and pays on www.4over4.com; use it when the buyer is ready to order printing with UCP. UCP create_checkout (2026-04-08): a checkout session from line_items, or from a cart with cart_id. It is requires_escalation: 4OVER4 is paid only by the buyer: the continue_url adds the lines to the buyer's own 4OVER4 cart and opens www.4over4.com/checkout, where the buyer uploads artwork now or later, ships and pays.

Tool call template

Replace each placeholder with a value matching the input schema. Only required parameters are included; add optional parameters as needed.

{
  "id": 1,
  "jsonrpc": "2.0",
  "method": "tools/call",
  "params": {
    "arguments": {
      "meta": "<meta>",
      "checkout": "<checkout>"
    },
    "name": "create_checkout"
  }
}

Input Schema

Name	Required	Description	Default
`meta`	Yes	Request metadata.
`checkout`	Yes

Output Schema

Name	Required	Description	Default
`id`	No
`ucp`	Yes
`links`	No
`status`	No
`totals`	No
`currency`	No
`messages`	No
`expires_at`	No
`line_items`	No
`continue_url`	No

Schema Changelog

Changes observed during successful MCP inspections.

First observedNov 13, 2026

TDQS

A4.1/5.0

Behavior5/5

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Beyond the annotations (write, non-idempotent, non-destructive), the description discloses the key behavioral trait: it is requires_escalation, the agent never collects payment, and the continue_url hands the buyer to their own 4OVER4 cart at www.4over4.com/checkout for artwork upload, shipping and payment. That is exactly the context an agent needs to set expectations.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Conciseness4/5

Is the description appropriately sized, front-loaded, and free of redundancy?

The purpose is front-loaded and the escalation/handoff detail is valuable, but the closing clause repeats the payment handoff already stated in the first sentence ('buyer finishes and pays' / 'ships and pays'), and the semicolon-chained phrasing is denser than needed.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Completeness4/5

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

For a checkout-start tool with an output schema present, the description covers purpose, escalation, and end-to-end buyer flow well. It omits prerequisites (e.g. authentication/profile requirements) and any note on retry/idempotency, which matter for a non-idempotent mutation.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Parameters3/5

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema description coverage is 50%, and the description clarifies that the session can be built either from line_items or from cart_id — an alternative relationship the schema does not spell out. However it says nothing about meta, ucp-agent profile, or the idempotency-key parameter, leaving half the surface to the schema.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Purpose4/5

Does the description clearly state what the tool does and how it differs from similar tools?

The description opens with a specific verb+resource: 'Starts a 4OVER4 checkout for print items', and clarifies that the buyer finishes and pays on www.4over4.com. It is distinguishable from siblings like get_cart or show_products, though it never explicitly contrasts with any named alternative.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Usage Guidelines4/5

Does the description explain when to use this tool, when not to, or what alternatives exist?

It gives a clear trigger condition: 'use it when the buyer is ready to order printing with UCP'. It also notes two input modes (line_items vs cart with cart_id) but does not state when to prefer one over the other, nor any when-not conditions.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.

All 4OVER4 tools Inspect

Try in Browser

One endpoint for every MCP toolRayrun runs every MCP server behind one URL and holds the credentials. Each call is decided per client, tool, and argument, then recorded.ray.runAd

Glama MCP Gateway

Add one secure layer between your agents and this server.

Resources

Need Help?