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

With no annotations, the description carries the full behavioral burden. It does disclose the data provenance ('FAA-public data') and enumerates the returned fields (model, engine, year, status), which is genuinely useful context. However, it says nothing about behavior when the N-number is unknown (error vs. empty result) or any rate/availability constraints on the upstream FAA source.

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?

A single front-loaded sentence with the resource and key identified immediately and the returned fields tucked into a parenthetical. No wasted words, though the parenthetical could have been a clean second clause rather than a field dump.

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 one-parameter, read-only lookup with no output schema, the definition is nearly sufficient: it identifies the data source and lists the fields an agent will receive, which compensates for the absent output schema. The remaining gap is not-found behavior, which is a meaningful but minor omission at this complexity level.

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 already documents n_number with an example (N12345), so the baseline is 3. The description reinforces that exactly one N-number is expected, but adds no format, casing, or validation detail beyond what the schema 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 names a specific verb-resource pair ('registration detail') and scopes it to 'one N-number', which implicitly distinguishes this single-record lookup from the batch-oriented 'search_registry' sibling. It never names that sibling explicitly, so the differentiation is inferred rather than stated.

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?

Usage is only implied: 'for one N-number' suggests a single-record lookup as opposed to a search, which hints at when to prefer this over search_registry. There is no explicit when-to-use, when-not-to-use, or named alternative, so an agent must infer the routing decision.

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