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

The description discloses an important behavioral trait: a call to the external Open-Meteo service. However, with no annotations to fall back on, it does not explain that the action is read-only, what format or unit the temperature is returned in, what happens on API failure, or that the other optional schema parameters are ignored. The basic behavior is stated, but beyond that is thin.

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 with no filler or repetition, and the core idea is front-loaded. It is appropriately short for a tool with a rich schema, but it could earn its place better by adding one clause, such as what the caller receives.

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?

For a tool with nine optional parameters, no annotations, and no output schema, this description provides only the high-level intent. It does not specify the output value, unit, whether the city must be internationally recognized, or how to handle failures—so an LLM cannot fully predict what will happen when the tool is invoked.

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 schema already documents all nine parameters individually, giving this a baseline of 3. The tool description itself adds little parameter meaning beyond naming a city, and it does not tell the agent to ignore the other eight parameters, but the schema-level descriptions are sufficient to avoid missing parameter documentation.

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?

"Current temperature for a city via Open-Meteo" clearly names a specific action and resource, so it is not a tautology. It does not explicitly distinguish itself from sibling tools like geo-hint or timezone, and the 9-parameter schema makes the intended resource less obvious, but the core purpose is clear.

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 wording implies usage whenever the agent needs the current temperature for a city, but it provides no explicit when-to-use, when-not-to-use, or alternatives. There are no exclusions or conditions such as 'only for a single point-in-time query' or 'not for forecasts', so an agent must infer the boundaries.

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