open-weather.getForecast

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

Annotations already declare readOnlyHint: true and idempotentHint: true, so the description does not need to restate that it is read-only. The description adds no further behavioral traits beyond the time horizon ('5-day') and target ('city'), which is minimal but not misleading.

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 fluff. Every word earns its place.

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 the tool's simplicity and the existence of an output schema, the description sufficiently covers what is needed. It does not explain location format or units, but these are likely covered by the output schema or other fields, and the description is adequate for a straightforward forecast retrieval.

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?

With zero parameters in the schema, the baseline is 4. The description mentions 'for a city,' but the schema lacks any parameter to specify it, which could be a minor gap. However, since there are no parameters to document, the description adds a reasonable amount of context.

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 gets a 5-day weather forecast for a city, using a specific verb and resource. It distinguishes itself from the sibling tool open-weather.getCurrentWeather, which implies current conditions, making the purpose unambiguous.

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 usage when a multi-day forecast is needed, but there is no explicit guidance on when to use this tool versus alternatives. It relies on the sibling naming to convey context, which is implicit rather than explicit.

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