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

With readOnlyHint/openWorldHint already covering safety, the description goes further and discloses the commercial and auth model: $0.002 USDC per successful call via x402 on Base, Solana or Arc, with failed calls free. That is exactly the kind of cost/payment behavior an agent needs before invoking.

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 tight sentences: what the record contains first, then source/caveat/pricing. No filler, and the most decision-relevant facts (scope, then cost) are front-loaded.

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?

An output schema exists, so return values needn't be explained, and annotations cover the read-only profile. Combined with the payment terms, data source and fitness caveat, nothing material is missing for correct invocation.

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 single nNumber parameter already carries an example format, so the schema does the heavy lifting. The description adds no syntax, normalization or validation detail beyond what the schema states, which is the expected baseline here.

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?

Names a specific resource (US FAA aircraft registry record) keyed by a specific identifier (N-number) and enumerates the returned fields. An agent can distinguish it at a glance from the many company/tender/court-record siblings.

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 'not for airworthiness decisions' line tells the agent what the data should not be used for, which is useful. But there is no explicit guidance on when to pick this over alternatives or on input prerequisites beyond the N-number, leaving usage largely implied by the resource name.

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