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

With no annotations, the description carries the full transparency burden. It discloses auth requirements, the legacy status, the server-side price re-verification, and the return of a Yoco or Ozow payment_url. It stops short of describing error behavior or side effects beyond order creation, so a 4 is appropriate.

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 compact and every sentence earns its place: legacy/auth warning, explicit alternative, usage condition, price re-verification note, and return value. It is front-loaded with the most important caveat and contains no filler.

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 the tool's complexity (legacy auth, nested items, price handling, payment providers) and the absence of annotations and output schema, the description covers the essential aspects for correct invocation: when to use, auth requirement, pricing behavior, and the returned payment_url. It is sufficiently complete for an agent to decide and call correctly.

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%, so the baseline is 3. The description adds semantic value by clarifying that unit_price_zar and total_price_zar are ignored and re-verified server-side, which is not evident from the schema alone. It also implies the items array is the core payload, but does not detail every nested field beyond what the schema already provides.

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 what the tool does: creates an order and returns a payment link, while immediately distinguishing itself from the preferred UCP flow (create_cart → create_checkout → complete_checkout). It specifies the legacy, auth-required nature and the single-call path, making it distinct from sibling checkout tools.

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?

Explicit usage guidance is provided: prefer the open UCP flow when no credentials are available, and use create_order only if holding a Bearer token and needing a single-call path. It also warns that agent-supplied prices are ignored, which is critical guidance for safe invocation.

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