get_checkout_url

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

No annotations provided, so description carries the full burden. It explicitly discloses the pre-launch behavior: 'Before launch, returns the launch date and early-access contact instead of a URL.' This is a key behavioral trait beyond the schema. It doesn't mention other side effects, but for a read-only getter this is adequate.

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?

The description is compact: a single sentence for purpose, a sentence for pre-launch behavior, and two parameter explanations. It front-loads the core purpose and adds only necessary details with no waste.

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?

The tool is simple with two parameters. The description covers the special pre-launch case, explains parameter sources, and the output schema exists to define return values. The description is complete for an agent to call it correctly.

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 0%, so the description must compensate. It fully explains both parameters: 'slug: A product slug from list_products, e.g. "film-shoot"' and 'tier_name: A tier name from that product's pricing_tiers, e.g. "Per-shoot"' – providing source, meaning, and examples for each.

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?

Description states 'Get the checkout URL for one pricing tier of one product' – a specific verb (get), resource (checkout URL), and scope (one pricing tier of one product). It also differentiates from sibling tools by focusing on checkout URL, clearly distinct from list_products (listing) and get_product (product details).

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?

Provides clear context by referencing that slug comes from list_products and tier_name from that product's pricing_tiers, implying the need to call list_products first. It doesn't explicitly state when not to use it or name alternatives, but the context is sufficient for correct usage.

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