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

Annotations already declare readOnlyHint=true and destructiveHint=false, so the safety profile is covered. The description adds 'Live' to indicate real-time data and 'any city' to indicate broad geographic coverage, but it does not disclose data freshness, latency, or potential limitations. Given the annotations, this is adequate, though not rich.

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 a single, front-loaded sentence that immediately conveys the core function. No filler or redundancy. It earns its place by listing specific data types, which is highly efficient.

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?

The tool is simple with optional parameters and an output schema, but the description lacks guidance on how latitude/longitude interact with city, or whether city is sufficient. While the output schema may cover return values, the incomplete parameter semantics leave a gap in overall context.

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 only 33% (only 'city' has a description). The description mentions 'any city' but does not explain the purpose or usage of latitude/longitude parameters. Since the schema does not document them either, the description fails to compensate for the low coverage, leaving two parameters semantically opaque.

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 'Live air quality for any city: US/European AQI, PM2.5, PM10, ozone' clearly states the tool provides air quality data, specifies the metrics (AQI, PM2.5, PM10, ozone), and distinguishes it from siblings like get_weather. The verb 'get' in the name plus the descriptive resource makes the purpose immediately obvious.

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 implies this tool is used when the user needs air quality data, but it does not explicitly state when to use it over alternatives (e.g., get_weather) or mention any exclusions. No when-not-to-use guidance is provided, so it relies on the user to infer the appropriate context.

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