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

Annotations declare the safety profile (not read-only, idempotent, non-destructive, closed-world), and the description adds real value on top: the order is created unpaid, the response is a checkout URL off-site on Stripe, and no print job is triggered until payment. That two-phase flow (order → external payment → production) is the key behavioral fact an agent needs. It does not say whether re-calling reuses or replaces an existing unpaid order, which matters given idempotentHint=true.

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 sentences, zero padding, both front-loaded with the highest-value facts: what is created, what is returned, and the payment gate. Nothing redundant with the schema or annotations.

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 no output schema, the description usefully describes the return value (checkout link) and the payment gate, which is enough to call this correctly. The one gap is that the proof being ordered is never a parameter, so an agent can't tell from the description how the proof is bound to the order.

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% and the single parameter already documents itself ("Price id (prs_...) from get_price"), so the description correctly doesn't restate it. Baseline 3 applies. It also leaves unexplained how the target proof is identified when only a price id is passed.

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?

Specific verb+resource ("Creates an unpaid order") plus the scope of what it operates on ("for an approved proof") and what it returns ("link to the checkout page on myimage2life.com (Stripe)"). This cleanly separates it from create_proof, create_design, get_order_status, and get_price.

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?

States preconditions implicitly but clearly: the proof must already be approved and paid via Stripe checkout, and "Nothing is printed before payment" tells the agent printing has not happened yet. No explicit when-not-to-use or named sibling alternative, so it stops short of a 5.

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