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

With no annotations provided, the description carries the full burden of behavior disclosure, but it only says 'Current temperature for a city via Open-Meteo.' It does not describe whether this is a read-only external call, what units the temperature is returned in, how the city name is resolved, or how the other schema inputs like ref, url, and feed are treated.

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 or redundancy. It is concise and to the point, though slightly under-specified for a tool with seven parameters and no other documentation.

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 seven schema parameters, no annotations, no output schema, and a narrow purpose, the description is incomplete. It omits required parameters, the exact output format or units, error behavior, and how the unrelated-looking parameters such as ref, url, feed, and host should be handled.

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 already describes all seven parameters, and the description adds only that the city parameter is the operative one and that the data source is Open-Meteo. It does not clarify how the remaining parameters relate to the tool or how they should be populated, so it provides little value beyond the schema.

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. Although it lacks an explicit verb like 'Gets' or 'Returns', the phrasing is specific enough to distinguish it from sibling tools such as geo-hint or web-fetch.

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 on when to use weather-hint versus alternatives like geo-hint or web-fetch, and no mention of conditions, exclusions, or prerequisites. The description only states the general function without helping an agent decide when to invoke it.

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