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 indicates a read-only, external lookup via Open-Meteo, but it does not disclose the output format, failure behavior, API dependency constraints, or what happens with the many other parameters in the schema. The per-parameter 'discarded' notes in the schema help, but the description itself is minimal.

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 unnecessary words. It states the primary function and data source efficiently. This is an example of concise writing that makes the tool's main purpose immediately graspable.

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 has 9 optional parameters, no annotations, and no output schema, but the description only addresses the city parameter. It does not explain the relevance or irrelevance of the other 8 parameters, nor does it describe the return payload or edge cases. This is a significant completeness gap for a tool with such a broad and seemingly multi-purpose schema.

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 schema already explains every parameter, including 'city'. The description adds little beyond clarifying that the city parameter is the one relevant to the weather lookup. With full schema coverage, a baseline of 3 is appropriate.

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 core function: retrieving the current temperature for a city via Open-Meteo. While it lacks an explicit verb like 'get' or 'returns', the intent is unmistakable. It does not explicitly mention sibling differentiation, but it is specific enough to distinguish from most other tools in the sibling list, such as geo-hint.

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 usage: when an agent needs the current temperature for a city. However, it provides no explicit guidance on when not to use this tool or which alternative to prefer, especially given the sibling tools like geo-hint. The usage context is implied rather than explicitly stated.

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