navi_weather

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

Without annotations, the description carries the burden of disclosure. It mentions the data source (Open-Meteo), the paid nature ($0.001 USDC per call on Base), and the output data types. This goes beyond minimal disclosure by flagging costs and real-time behavior, though it omits error handling or rate limits.

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 concise: two sentences plus a payment note. It is front-loaded with the core purpose, then gives input method and output details. Every sentence adds value with no filler or redundancy.

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?

There is no output schema, but the description lists key return fields (temperature, humidity, wind, precipitation, conditions) and the time range (3-day forecast). It also covers input options and payment. While it doesn't specify units or response structure, it enough for a weather tool.

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 covers 100% of parameters with descriptions, giving the baseline of 3. The tool description repeats the idea of using 'city name or lat/lon coordinates' but adds no new semantic details beyond the schema. The schema already explains that lat/lon are used together and that location is an alternative.

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 a specific action: 'Real-time weather data and 3-day forecast for any location worldwide.' It names the resource (weather) and differentiates from sibling tools, none of which are weather-related. The verb 'returns' plus the list of output fields makes 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 provides clear context: it accepts city name or lat/lon coordinates and returns weather info. It implies usage for any weather need, though it lacks explicit 'when not to use' or alternative tool references. Since no sibling tool handles weather, this is sufficient contextual guidance.

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