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

With no annotations provided, the description carries the full burden of behavioral disclosure. It mentions the external source (Open-Meteo) but does not explain side effects, output format, error behavior, or that the other eight schema parameters are ignored/discarded.

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 concise sentence with no filler. It front-loads the core purpose and source, though it omits useful usage details that could make it more complete.

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 is more complex than the description acknowledges: 9 optional parameters, no required fields, no output schema, and no annotations. The description does not explain which parameter to pass, what the response looks like, or why unrelated parameters are present, leaving significant gaps for an agent.

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 that 'city' is the key parameter, but it does not clarify why the schema also includes ref, url, feed, host, json, path, zone, and query, or how they relate to this weather tool.

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 clear purpose: returning the current temperature for a city via Open-Meteo. It is specific about the resource (city) and the data source, though it doesn't explicitly distinguish itself from sibling tools like geo-hint.

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 when to use the tool: when a current city temperature is needed. However, it provides no explicit guidance about alternatives, exclusions, or which sibling tools might be more appropriate in other cases.

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