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

Annotations already cover readOnlyHint, idempotentHint, and destructiveHint, so the safety profile is structurally disclosed. The description adds useful context beyond annotations: no authentication required, US Government public domain source, and the exclusivity of the three lookup modes. No contradiction with annotations.

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?

Four sentences, each serving a distinct purpose: purpose, returned fields, use case, and input/source. The structure is logical and front-loaded, though the parameter summary slightly duplicates schema descriptions.

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?

Complete for a zero-required-param read-only lookup: purpose, return fields, input alternatives, use case, source, and auth requirements are all present. An output schema exists, so the return-value structure does not need to be spelled out in the description.

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% with per-parameter examples ('KJFK,KLAX', '25,-125,50,-65') and mutual-exclusivity guidance already included. The description restates these formats and options without adding materially new information, so it stays at the baseline for high 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?

States a specific verb-resource pair ('Look up aviation weather observation stations') and enumerates the exact metadata returned (ICAO, IATA, FAA, WMO, coordinates, etc.). It distinguishes itself from weather-data siblings by positioning itself as station discovery 'before calling METAR or TAF 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?

Explicitly frames the tool as a prerequisite discovery step for METAR/TAF calls and requires choosing one of three mutually exclusive inputs ('Provide one of: ids, bbox, state'). It gives clear context but does not name the alternative sibling tools explicitly, so when-not-to-use guidance is implied rather than fully explicit.

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