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

With no annotations, the description carries the behavioral burden and does provide useful facts: it uses Open-Meteo, requires no API key, and focuses on specific AQI metrics. It does not disclose rate limits, error behavior, or output format, and the parenthetical 'no key' is not a substitute for a fuller behavioral note.

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 one compact line with no filler: metric names lead, coordinate context follows, and the source/auth fact is parenthetical. Every phrase earns its place.

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 main invocation input, q, is undocumented and ambiguous despite the output schema being present and complexity being low. An agent would have to guess whether q is a coordinate string, a query, or something else, which makes the definition incomplete in practice.

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 only parameter 'q' has no schema description, and the description's phrase 'at coords' is only an indirect clue that q may encode coordinates. The format of q (e.g. latitude,longitude) and its optional/default semantics remain unspecified, so schema coverage being 0% is not compensated.

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 identifies a specific resource ('Air Quality') and the values it returns (PM2.5/PM10/European AQI) at coordinates, which is far better than a tautology. It lacks an explicit verb and does not name sibling tools, so it stops short of full differentiation.

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?

'at coords' gives an implied context: use this when a coordinate location's air quality is needed. There is no explicit comparison to related sibling tools such as weather or marineweather, and no when-not-to-use guidance.

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