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 mentions the external data source (Open-Meteo) but does not state whether the operation is read-only, what happens to the input, or any rate limits or side effects. The schema's mention that the city is 'discarded after the call' is not reflected in the description.

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 words. The core purpose is front-loaded, and the mention of the data source is succinct. It is an appropriately sized definition for a simple hint tool.

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 description tells the agent what the tool returns, but the input schema contains six unrelated parameters with no explanation of why they exist or whether they are ignored. Without an output schema or annotations, the description leaves ambiguity about which parameter to pass and how the tool handles the others. This is a clear gap in completeness.

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 high (every property has a description), so the baseline is 3. The tool description itself does not mention parameters or clarify which of the seven schema properties are relevant. However, the phrase 'for a city' aligns with the 'city' property description, and the schema provides definitions for all parameters.

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 resource and purpose: it returns the current temperature for a city using Open-Meteo. The weather-specific wording distinguishes it from sibling tools like geo-hint. It lacks an explicit verb such as 'Get' or 'Return', so it stops just short of a perfect score.

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 usage is implied by the description: use this tool when you need a city's current temperature. However, there is no explicit guidance about when not to use it, nor any mention of alternative tools for similar tasks. The usage is clear but not articulated beyond the purpose itself.

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