lookup_aircraft

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

The description discloses key behavioral details: position data is only included when querying a specific aircraft, limit cap (500 max, 50 for free keys), and the range of return fields. However, since there are no annotations, it could mention that this is a read-only operation and any potential freshness of data. The lack of contradiction and the added context elevate it above average.

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 starts with a clear trigger statement and is well-organized with use cases and input guidance. While it is somewhat verbose, every sentence serves a purpose. It could be tightened slightly, but the structure aids readability and comprehension.

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?

Given 8 parameters and no output schema, the description adequately covers how to use the tool for both specific aircraft and fleet queries, lists return fields, and addresses a common ambiguity (airline name vs. code). Without an output schema, it doesn't detail the exact response format, but the listed fields and behavioral notes make it functional for the agent.

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?

The description adds significant meaning beyond the schema: it groups parameters (reg_number/hex/msn for specific aircraft vs. airline codes for fleet listing), clarifies the position inclusion condition, and advises on resolving airline names. This context is crucial for correct use and goes well beyond the baseline 3 given 100% schema coverage.

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 looks up aircraft in a fleets database and lists the specific fields returned (type, model, manufacturer, etc.). It distinguishes from sibling tools by specifying its domain (aircraft lookup vs. airports/routes/flights) and providing a trigger for automatic invocation when the user asks about a specific aircraft or airline fleet.

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 when to use (user asks about aircraft or airline fleet) and when not to (resolving airline name via get_airline_info first). It provides concrete use cases with examples, and explains the different input modes (specific aircraft vs. fleet listing). This gives the agent clear decision criteria.

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