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

With no annotations present, the description must carry the behavioral burden. It does state that the tool uses Open-Meteo and provides current temperature, which is the essential behavior. It does not reveal whether the call is live, how failures are handled, or that non-city parameters are ignored, but the read-only, stateless nature is reasonably inferable.

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 with no filler. It efficiently states the output, the target subject, and the data source.

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?

Despite the rich schema, the description leaves key invocation context unstated: it does not say that 'city' is effectively required, what temperature unit is returned, or how city names are resolved. The presence of nine optional parameters with mostly irrelevant descriptions makes this omission more confusing for an agent.

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 meaningful descriptions for all 9 parameters, so the baseline is 3. The tool description adds no additional parameter-level meaning and does not explicitly state that only 'city' is relevant, though the schema already marks the others as discarded.

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 identifies the tool's core function: returning a city's current temperature via Open-Meteo. It is specific enough to differentiate weather-hint from generic 'hint' siblings, though it does not explicitly contrast it with any alternative tool.

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 intended use case is implied: when an agent needs the current temperature for a city, this is the tool to use. However, it gives no explicit guidance on when not to use it, no prerequisite conditions, and no mention of how to handle ambiguous city names or units.

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