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

With no annotations, the description carries the full burden of behavioral disclosure, but it only states that the tool returns a temperature. It does not mention that some parameters are discarded (as indicated in the schema), whether it makes external network calls, what the response format is, or any side effects. The description adds minimal behavioral context beyond the one-line function.

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 that gets to the point immediately. It is concise and free of fluff. However, it omits essential context about the other parameters, so the conciseness is at the expense of completeness. Still, as a stylistic metric, it is well-structured and brief.

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 parameters, no output schema, and no annotations. The description only covers the weather scenario, leaving the purpose of the other eight parameters unexplained. An agent cannot know which parameters to supply, how they interact, or what the expected response is. This is severely incomplete for a multi-parameter tool.

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 each parameter already has a description. The tool description adds no extra meaning to the parameters; it only mentions the city parameter implicitly. Since the schema does the heavy lifting, the baseline of 3 is appropriate—the description does not compensate for the lack of clarity about why many parameters are present.

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 primary purpose: getting the current temperature for a city via Open-Meteo. However, the input schema exposes nine unrelated parameters (ref, url, json, etc.) with no explanation in the description about their role or whether they are part of this tool's actual function. This ambiguity means an agent cannot reliably determine what the tool does beyond the weather aspect, especially since many siblings suggest specialized hint tools.

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 provided on when to use this tool versus alternatives. The description does not mention any prerequisites, exclusions, or how it differs from sibling tools like geo-hint or timezone. An agent has no basis to decide whether weather-hint is the right tool for a given request.

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