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

No annotations, so the description carries the full burden and largely meets it: it discloses server-side price computation ('never send prices'), the idempotency contract, the payment channel, and the redirect-vs-QR rendering behavior. It omits auth/permission requirements, failure semantics, and rate-limit behavior.

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?

Four short sentences, each load-bearing: creation, pricing rule, idempotency, and return/rendering contract. The most decision-relevant constraints (prices computed server-side, idempotency) are front-loaded with 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?

For a 7-parameter mutation tool with a nested receiver object and no output schema, the description covers the essential workflow: pricing, idempotency, return values, and client rendering. Remaining gaps are auth requirements and error/retry failure behavior.

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 only 43%, so the description must compensate. It valuably explains that idempotency_key may arrive as a header or body field and that prices must never be supplied (clarifying max_price's role indirectly), but qty, merchant_id, product_id, and the nested receiver address fields get no added meaning.

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 order') and immediately adds distinguishing scope facts: the server computes amounts, payment is WeChat, and the response carries a pay_url. It never names a sibling tool, so the agent must still infer separation from the many cps_* order/convert 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?

Gives concrete operational context: an Idempotency-Key is required so retries don't double-order, and render_hint tells the host whether to show a QR or redirect. It does not state when NOT to use it or which sibling (e.g. cps_*_orders) is the read-side alternative.

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