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

Annotations already declare readOnlyHint=true and openWorldHint=false, so safety and closed-dataset behavior are covered. The description adds genuinely useful scope constraints (US-only, turbine aircraft only) and previews the returned fields, but says nothing about multiple matches when searching by owner name, result limits, or how the two parameters interact.

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 lookup key stated before the returned fields, and no filler. The parenthetical alternative mode is slightly compressed but does not obscure the meaning.

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 two-parameter read-only lookup with no output schema, the description is close to sufficient: it defines both inputs, the domain restriction, and the shape of the response. The remaining gap is ambiguity around owner-name searches returning multiple aircraft and any result-size behavior.

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 0%, so the description must carry parameter meaning, and it largely does: n_number is identified as an N-number and owner as a registered owner name, with the parenthetical framing them as alternative lookup modes. It falls short of stating whether the parameters are mutually exclusive or which takes precedence if both are given.

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 (look up) and a specific resource (US turbine aircraft by N-number or registered owner name), then enumerates the exact fields returned: registered owner, owner-trustee status, model, and FCC radio altimeter rebate category and proposed rebate. This is clearly distinct from siblings like who_owns_home or lookup_organization, which target different entity types.

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 implied rather than stated: an agent can infer this is the tool for aircraft ownership questions, and the parenthetical shows two lookup modes (N-number vs. owner name). However, there is no explicit when-not guidance, no mention of the sibling tools, and no statement about which mode to prefer or what happens if both or neither parameter is supplied.

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