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

Annotations already declare readOnlyHint, idempotentHint, and non-destructive safety, so the description need not repeat those. It adds valuable context: the tool checks payment status and conditionally returns a permanent download link, which is behavior beyond the annotations. It doesn't mention potential error states (e.g., session not found, unpaid session) or rate limits, preventing a 5.

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?

Single sentence, front-loaded with the prerequisite (session id) and the outcome. No wasted words; every clause contributes.

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 simple one-parameter read-only tool with rich annotations and no output schema, the description covers the essential behavior (payment check and download link return). It could mention what happens when unpaid (e.g., returns an error or a status) but the core is complete.

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 schema description already states the parameter is a Stripe Checkout session id from create_checkout with a pattern '^cs_'. The description repeats the 'cs_…' format but adds no syntax or meaning beyond the schema, so the baseline 3 is appropriate.

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 (reports/checks) and resource (Stripe Checkout session), and clarifies the exact conditions: whether it is paid, and if so returning a download link. An agent can distinguish this from create_checkout and buy_dataset without schema inspection.

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?

The description implicitly tells the agent to use it with a session id from create_checkout (schema also says 'from create_checkout'). It doesn't explicitly say when NOT to use it (e.g., before checkout is created) or name alternatives, but the input requirement and purpose are clear enough to guide selection.

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