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

Annotations already specify readOnlyHint=true and idempotenceHint=true, so the description's main behavioral contribution is showing that the tool fetches live data from Open-Meteo. It does not discuss units, error handling, or the fact that most schema params are discarded, but the annotation cover safety.

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?

A single sentence with no fluff. The core action and source are stated immediately and every word contributes.

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 a seven-parameter schema with many apparently unused fields, an empty output schema, and no usage guidance, the description is too thin to fully orient an agent. It leaves unclear which parameters are required, what the response shape will be, and how to recover from missing or invalid city names.

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 low (20%), and the description only mentions 'city'. It does not clarify which of the seven input parameters should be populated, nor does it explain the role of the many unrelated parameters such as ref, url, feed, host, json, and path beyond what the schema itself says.

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 that the tool returns the current temperature for a city and identifies the data source as Open-Meteo. This is specific enough to distinguish the tool from generic hint tools, though it does not explicitly name sibling alternatives.

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?

There is no guidance about when to use this tool versus sibling tools like geo-hint or web-fetch. The intended use is only implied by the phrase 'for a city', with no explicit conditions or alternatives.

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