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

No annotations are provided, so the description carries full responsibility for behavioral disclosure. It identifies Open-Meteo as the source but does not describe whether the tool makes a network request, what units or format the temperature is returned in, how errors are handled, or that the other schema fields are explicitly discarded. This is not enough transparency for a tool with such a broad schema.

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 single sentence is short and front-loaded, with no filler. However, it is under-specified for a nine-parameter tool, and the brevity contributes to the ambiguity rather than serving as a model of efficient communication. It is concise, but not appropriately sized for the tool's complexity.

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 nine optional parameters, no annotations, and no output schema, the description omits nearly all context needed for correct invocation. It does not explain which parameter drives the weather result, what the response looks like, or how this tool relates to sibling tools like geo-hint or timezone. An agent cannot reliably choose and call this tool based on the 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 description coverage is 100%, so the baseline is 3 even without additional parameter details in the tool description. The description itself adds no parameter-level meaning and even creates tension by implying 'city' is the core input while it is only one of nine optional fields. The schema already explains the discard behavior, so the description does not need to compensate, but it also does not improve parameter understanding.

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 concrete operation — returning current temperature for a city — and names the data source (Open-Meteo), which gives the agent a clear sense of the tool's purpose. It is distinguishable from likely siblings like geo-hint or utc-time by its weather-specific focus. However, it does not acknowledge the schema's many unrelated optional parameters, which creates some ambiguity about the tool's actual behavior.

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 about when to use this tool versus alternatives. The description does not mention that only 'city' is relevant, nor does it say what to do if the agent has a URL, host, JSON, or other input. With all nine parameters optional, the agent is left to infer the correct invocation context.

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