Hourly Forecast

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

With no annotations, the description carries the behavioral disclosure burden. It adds useful behavior beyond the schema: covered variables, per-row absolute time, ISO-8601 format, and Brussels timezone. It does not detail units or error behavior, but the output schema likely covers return structure.

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?

Three short sentences with no filler: purpose, covered metrics, and time format. Each sentence supplies distinct, useful information and the most important scoping detail is front-loaded.

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 output schema exists and all parameters are fully documented, the description is nearly complete. It explains what the forecast contains and how time is represented. It could be stronger by explicitly addressing location resolution between commune and coordinates, though the schema already hints at it.

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 100%, so the schema already documents commune, latitude/longitude, and hours including the clamping range. The description adds no parameter-specific meaning, so the baseline of 3 is appropriate.

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 opens with a specific verb and resource: 'Return an hourly weather forecast for a location in Belgium.' The temporal scope 'hourly' clearly distinguishes it from siblings like daily_forecast and current_conditions, and the Belgium scope narrows the domain.

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 fine-grained hourly data is needed, but it never explicitly tells the agent when to choose this over daily_forecast or current_conditions. No when-not or alternative guidance is provided, only an implied temporal fit.

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