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

Annotations mark it as read-only and open-world. Description adds value by specifying the exact return fields (paid, package, deposit, order_token) and the exclusivity of payment status determination. No contradictions.

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 sentences, front-loaded with the main action, concise and informative. Every sentence adds necessary detail without 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?

Description covers the main purpose, return values, and usage of the output. With an output schema present, it does not need to detail return values further. Slight gap on what 'package' and 'deposit' represent, but likely covered by schema.

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% with a clear description of session_id. Description does not add extra meaning about the parameter, but baseline is met.

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 clearly states the verb 'verify' and resource 'payment after checkout'. It distinguishes from sibling tools by specifying the exclusive role in establishing payment status. The mention of returning an access token adds specificity.

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: payment status can only be established here, implying this tool is necessary for that purpose. It also indicates how to use the output token with other tools. However, it does not explicitly exclud others or state when not to use it.

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