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

The description contradicts the annotations: readOnlyHint=true but the description states the tool 'triggers order fulfillment', implying a write/side effect. This is a serious inconsistency. The description also adds useful context like polling interval and authentication, but the contradiction overrides any positive contribution.

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 three sentences and each sentence provides meaningful information without fluff. It is front-loaded with the core purpose and includes necessary polling and authentication details.

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?

Despite having an output schema and good schema coverage, the description misleads about the tool's side effects by claiming it triggers order fulfillment while annotations say read-only. This fundamental inconsistency makes the description incomplete and unreliable for an agent, even though it covers how to use the tool.

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 100%, so baseline is 3. The description adds some value by mentioning authentication and referencing checkout_create for payment_url, but it doesn't substantially enhance parameter understanding beyond what the schema already provides.

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?

The description clearly states the tool checks the payment status of a checkout session, using the specific verb 'check' and resource 'payment status'. It distinguishes itself from siblings by referencing polling after checkout_create and the payment_url.

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 explicitly says to use this tool for polling after sending a payment link and even provides the polling interval (every 5-10 seconds). It lacks explicit when-not-to-use or alternative tools, but the context is clear enough.

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