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

With no annotations, the description carries the full transparency burden, but it only reveals that Open-Meteo is used. It does not disclose that the other parameters are discarded after various checks, that all parameters are optional, that the operation is read-only, or what the response looks like. The mismatch between the weather-focused description and the generic schema further reduces transparency.

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 one sentence, front-loaded with the main purpose, and free of redundant wording. It is concise and easy to scan, though slightly too sparse given the tool's complex schema and lack of annotations.

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 no annotations, no output schema, nine optional parameters, and many sibling tools, yet the description only covers the city-temperature use case. An agent is left without guidance on which parameter to supply, what the return value is, and how this tool fits relative to siblings. This is not complete enough for confident 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?

Schema description coverage is 100%, so the baseline is 3. The description adds no real parameter semantics beyond pointing to 'city', and it does not clarify which of the nine optional parameters matter for the advertised weather use or how the others should be interpreted. It neither improves nor strongly harms the schema's own 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?

The description names a specific resource ('current temperature'), a target ('a city'), and a source ('Open-Meteo'), so an agent can tell the tool is about retrieving city temperature. However, it does not explicitly distinguish this from sibling hint tools, and the broad schema with eight unrelated parameters slightly weakens the clarity.

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 gives no guidance on when to use this tool versus alternatives such as geo-hint or timezone. The only implicit cue is 'current temperature for a city,' which is not enough to establish selection criteria, exclusions, or preferred use cases.

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