weather_at

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

With no annotations, the description adds important behavioral context: data sources, time range limitations, and dependency on local logs. It does not mention read-only nature or rate limits, but the provided details are substantial.

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 three concise sentences. The first states purpose and output fields, the second gives the parameter format, and the third explains data sources and limitations. No extraneous words.

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 an output schema exists (not shown), the description does not need to explain return values. It covers data sources, time constraints, and the 'when' format. However, it omits the 'city' parameter and does not explicitly state that the tool is a read-only operation, which would be helpful without annotations.

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 coverage is 0%, so the description must document both parameters. It explicitly describes the 'when' format but never mentions the 'city' parameter, which has a default but is not explained. This is a significant gap.

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 queries historical weather conditions at a specified time, listing specific fields (temperature, humidity, dew point, heat stress). It is distinct from siblings like weather_now and weather_forecast.

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 provides the required format for the 'when' parameter and explains data source limitations (official API only 24 hours, local logs needed for earlier times). It implies when to use this tool but does not explicitly exclude alternative weather tools.

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