Create a payment link

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

Annotations already declare this is a non-read-only, non-destructive, non-idempotent, closed-world create operation. The description adds genuinely new behavior: each visit to the link spawns a separate checkout session, and the link terminates itself on `max_uses` or `expires_at`. It stays silent on the idempotency behavior and what is returned, so it adds real value but not a complete behavioral picture.

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?

Three tight sentences, front-loaded with the core definition before the configuration rules. Every sentence carries distinct information: what it is, how pricing works, and how the link expires.

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 12-parameter create tool with no output schema and low schema coverage, the definition covers the essential decision points (pricing mode, expiry, usage cap). The gaps are the unexplained URL callbacks and the `split` rule, plus no indication of what the created link object contains – acceptable but not exhaustive.

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 33% across 12 parameters, so the description must carry weight – and it does for the highest-risk semantics: the mutual exclusivity of fixed `amount` versus the `min_amount`/`max_amount` range, plus the stopping conditions for `max_uses` and `expires_at`. It leaves `split`, `metadata`, `cancel_url`, `success_url`, and `name` unexplained, so it compensates partially rather than fully.

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 (create a payment link) and immediately defines what that is: a reusable hosted page where each visit starts its own checkout session. That reusability framing implicitly separates it from create_checkout_session, but no sibling is named, so the differentiation is inferential rather than explicit.

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 useful configuration guidance: use a fixed `amount`, or omit it and set `min_amount`/`max_amount` to let the customer choose, and use `max_uses`/`expires_at` to auto-stop the link. That is conditional logic for parameters, not tool-selection guidance – nothing says when to reach for this versus create_checkout_session or update_payment_link.

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