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

Annotations declare write/idempotent/open-world/non-destructive, and the description adds genuinely new behavioral context beyond them: the order is created UNPAID and the only payment path is the customer completing checkout at Stripe. It does not cover retry/idempotency semantics (requestId) or what the returned URL looks like, but the two-phase payment disclosure is real added value.

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?

Two short, front-loaded sentences with zero filler; the core action comes first and the payment-flow constraint second.

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?

With a 100% covered schema, an output schema (which handles return values like the Stripe URL), and annotations covering the write/idempotent profile, the description is nearly sufficient. The remaining gap is that it never states where the line-item selectors must come from (compose_preview / search_designs), leaving the prerequisite chain to the schema descriptions.

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 description coverage is 100%, so the schema fully documents items, shippingAddress, email and requestId. The description adds no parameter-level meaning beyond what the schema already states, so the baseline 3 applies.

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+resource ('Create an unpaid order') plus the notable output artifact ('Stripe payment URL'). It is clearly distinct from the sibling read/prep tools (compose_preview, get_product_blueprint, search_designs), though it never names them or explicitly contrasts itself.

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?

Usage is implied: the second sentence clarifies that the caller does not pay here and that the customer pays at Stripe, which tells the agent this is the order-placement step. However there are no explicit when-to-use/when-not rules, no statement of prerequisites (e.g. needing a compositionId from compose_preview or a finishedProductId from search_designs), and no mention of alternatives.

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