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

There are no annotations, so the description carries the full burden of behavioral disclosure. It only says 'via Open-Meteo,' which implies a network call, but does not disclose that other parameters are discarded, whether there are rate limits, or what the response format is. The schema notes 'discarded after the shape check' for many params, but the description does not surface this key behavior.

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 sentence, which is concise, but it is under-specified rather than appropriately sized. It lacks critical information about the tool's full behavior and parameter usage. The front-loaded core statement is clear, but the brevity comes at the cost of completeness.

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?

With 9 parameters, no output schema, no annotations, and a complex set of sibling tools, the description is completely inadequate. It does not explain the full functionality, the purpose of each parameter, the output format, or how to use it correctly. An agent cannot reliably select or invoke this tool based on this description alone.

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 coverage is 100%, so the baseline is 3. However, the description only mentions the city parameter and ignores the other eight parameters entirely. It does not help the agent understand why those parameters exist or how they relate to the weather hint functionality. The schema descriptions are self-explanatory, but the description adds no value beyond them and actually misleads by implying only city is relevant.

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 states a specific verb and resource: 'Current temperature for a city via Open-Meteo.' This is clear about the core function, but it does not differentiate from siblings like geo-hint or timezone, and the schema includes many unrelated parameters (ref, url, json, etc.) that are not mentioned, creating ambiguity about the tool's actual scope.

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?

No guidance is given on when to use this tool versus alternatives. The description does not mention any conditions, exclusions, or when not to use it. With 28 siblings, the lack of usage guidance is a significant omission.

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