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

With no annotations, the description carries the full burden and does well: it discloses that a cart is seeded server-side, that a HUMAN reviews and pays at the returned URL, that no payment is taken, no order is placed, and that prices exclude VAT. It omits auth/permission requirements and what happens on repeat calls or existing carts.

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?

Front-loaded with the core action and return value, and each sentence adds information (mechanism, payment scope, plan-type rules, VAT). The middle sentence is dense and comma-heavy, but no sentence is 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?

For a 7-parameter mutation-style tool with no annotations and no output schema, the description covers the essential flow, conditional requirements, and the returned URL. Gaps remain around currency/domain semantics, configSelections, and the absence of any auth or error-handling context.

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 very low (14%), so the description must compensate, and it does for the critical parameters: packageKey is required, siteDomain is conditional on hosting, and domain is unused for licences. It leaves currency, billingCycle format, configSelections shape, and add-on semantics largely to the schema.

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?

States a specific verb and resource ('Start an order for a configured hosting or licence plan') and immediately defines the mechanism: it seeds a cart server-side and returns a checkoutUrl. This clearly separates it from sibling read/quote tools like quote, get_plan, and order_status.

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?

Gives concrete conditional guidance: a hosting plan requires siteDomain while a licence takes no siteDomain or domain and is billed annually. It also clarifies scope by stating the tool takes no payment and places no order. It never explicitly names an alternative sibling (e.g. quote) or states when not to call it, so it stops short of full routing guidance.

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