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

The description discloses the return fields (name, city, country, coordinates) which goes beyond the annotations. It also mentions the data source and license (CC0), providing additional transparency about the tool's behavior.

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 is concise, one sentence, with the main action upfront and additional details following. It avoids unnecessary words and is well-structured.

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 simple lookup tool, the description is complete: it specifies the input, the output fields, and the data source. Combined with the annotations indicating read-only and idempotent behavior, an agent has sufficient context to use the tool effectively.

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 repeats the parameter description from the schema ('ICAO ident or IATA code') without adding further detail about formats or examples. Since the schema already covers the parameter, the description adds no new semantic meaning.

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's purpose: resolving an airport by ICAO or IATA code. It uses a specific verb 'resolve' and identifies the resource (airport) and the data source (OurAirports). This distinguishes it from siblings like accident search tools.

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 does not provide any guidance on when to use this tool compared to alternatives. It only describes what it does, but does not explain scenarios or criteria for selection, such as needing airport details vs accident records.

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