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

Annotations already cover read-only, idempotent and open-world traits, so the description's real contribution is the coverage caveat: FAA delay data is US-only and non-US airports return weather alone. That is a genuinely useful behavioral constraint an agent cannot get from the annotations. It stops short of describing rate limits or data freshness beyond 'latest observation'.

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?

Front-loaded trigger sentence, then example queries, then return contents, then the coverage caveat. Four tight sentences with no filler and a clear ordering from 'when' to 'what you get' to 'limitations'.

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?

A single-parameter read tool with full schema coverage, an existing output schema, and annotations carrying the safety profile. The description adds the one thing structured data lacks – the US-only FAA limitation – so an agent has everything needed to call and interpret it correctly.

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 100% and the parameter documents IATA/ICAO format identically, so the description is largely redundant here. It does reinforce that either code system is accepted, but adds no syntax or validation detail beyond the schema pattern.

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?

States a specific verb+resource ('Get airport status') and enumerates exactly what it covers: FAA delays/ground stops/closures plus METAR/TAF weather. Concrete example queries ('is JFK delayed?') make the domain unambiguous and separate it from the unrelated siblings (feedback, advisories, travel advice).

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?

Opens with an explicit trigger condition ('Use this when the user asks about delays, closures or weather at an airport') and adds a when-not boundary ('For general information, not flight planning'). It does not name or defer to any sibling tool, so no alternatives are routed explicitly.

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