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

No annotations are provided, so the description must carry the full behavioral burden. It only states the function (retrieving temperature) and does not disclose side effects, error handling, rate limits, or what happens with invalid cities. The schema mentions that many parameters are 'discarded', but that is not reflected in the description, leaving the behavior opaque.

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, concise sentence with no fluff, which is appropriately sized for a simple tool. However, it lacks any structural elements like usage context or examples, making it efficient but minimal.

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?

Given the tool has 9 optional parameters, no output schema, and no annotations, the description is severely incomplete. It doesn't specify which parameters are needed, what the output looks like, or any constraints. An agent would have no way to correctly invoke this tool beyond guessing 'city' is the intended input, and the other parameters remain unexplained.

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?

Although schema description coverage is 100%, the tool description adds no meaning beyond the schema and actually creates confusion. It only mentions 'city', while the schema defines eight other parameters with unrelated descriptions (e.g., 'Git ref name', 'JSON text to validate'). The description does not clarify which parameters are relevant or how they relate to the stated weather purpose.

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 action (get current temperature) and the resource (a city via Open-Meteo), making the core purpose apparent. However, it does not differentiate from sibling tools like geo-hint or timezone, and the schema's inclusion of many unrelated parameters (ref, url, json, etc.) muddies the purpose, even though the text itself is specific.

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 provides no guidance on when to use this tool versus alternatives, nor any conditions or prerequisites. It is a single statement with no exclusionary or contextual information to steer an agent's decision.

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