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

No annotations are provided, so the description carries the full burden of behavioral disclosure. It only states that the tool provides a current temperature via Open-Meteo, but does not disclose that this is a read-only external API call, any rate-limit or auth considerations, how city names are resolved, or that most of the nine input-schema fields are irrelevant or discarded. The behavioral picture is incomplete.

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, focused sentence with no filler. It front-loads the core purpose and names the provider, which is efficient for an agent scanning tool definitions. Every word 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?

There is no output schema and no annotations, so the description should compensate by explaining the return value and any key invocation requirements. It only says 'current temperature,' omitting units, response format, and the fact that city is the operative parameter among nine optional schema fields. The description is minimal and leaves important operational context unspecified.

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%, so the baseline is 3. The description's mention of 'city' adds little beyond the schema, which already describes the city parameter as 'City name for a public weather hint; discarded after the call.' It does not meaningfully clarify which of the nine parameters to use or how they relate.

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 specific purpose: returning the current temperature for a city, with the data source (Open-Meteo) named. It differentiates the tool from siblings like geo-hint or timezone by focusing on temperature. It is not a tautology and provides a concrete resource and operation.

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 gives a clear context for when this tool is appropriate: when a current temperature for a city is needed. It does not explicitly name alternatives or provide exclusions, but the purpose is specific enough that an agent can infer the right situation. It stops short of a 5 because no explicit 'when not to use' guidance is given.

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