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

Annotations already declare readOnlyHint, idempotentHint, and non-destructive nature. The description adds context by clarifying it does not charge money and that payment vs. placement are separate stages, which goes beyond the annotations. It could further describe the meaning of 'state', but with output schema present, this is sufficient.

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 concise sentences, front-loaded with the core purpose and key constraints. Every clause adds value: state checking, no checkout re-open, no charge, and the payment/placement distinction. No redundancy.

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 single-parameter, read-only tool with an output schema, the description covers what the tool does, what it does not do, and the context of its use (post-creation). The distinction between payment and placement gives the agent necessary domain context. Nothing essential is missing.

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 0%, so the description must compensate for the sole parameter. It mentions 'by intent_id' and connects it to the previously created link, adding minimal meaning. However, it does not explain what intent_id represents beyond that or how to obtain it, so it only partially compensates for the lack of schema documentation.

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 a specific action (checking state of a protected link) with a clear resource (previously created link by intent_id) and explicitly distinguishes from reopening checkout. This differentiates it from sibling tools like prepare_checkout.

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?

Clearly implies it is used after a checkout has been created, and explicitly says it avoids reopening checkout, which guides selection against prepare_checkout. However, it does not name alternative tools or state when not to use it, so it stops short of explicit exclusions.

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