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 explaining behavior. It does not mention that this is a live external lookup, that other input fields are discarded, what units the temperature is returned in, or any rate/error behavior. 'Via Open-Meteo' hints at an external service, but significant behavioral detail is missing.

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 with no filler, repetition, or extraneous detail. It efficiently states the operation, the target input, and the data source.

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 nine optional parameters, no output schema, and no annotations, the description is too sparse. It does not tell the agent which parameter to populate, that the other parameters are effectively ignored, or what the return format looks like. This leaves substantial room for mis-invocation.

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?

The input schema has 100% description coverage, so all parameters are already documented structurally. The description adds no new parameter meaning; it only repeats that a city is the relevant location input, which the city field description already states.

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 tool's function: get the current temperature for a city, and it names the data source (Open-Meteo). It does not explicitly distinguish itself from siblings like geo-hint or web-fetch, but the weather-specific language makes the core purpose obvious.

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 description implies the tool should be used when a current city temperature is needed. It provides clear functional context, but it gives no explicit when-not-to-use guidance or alternative tool routing, so it does not reach a 5.

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