nws_forecast

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

Annotations already establish read-only, idempotent, non-destructive behavior. The description adds meaningful output context by naming the period structure (~14 periods), the included fields (temperature, wind, precipitation probability, text), and the units (°F, mph), which is valuable beyond the structured metadata.

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?

Two efficient sentences front-load the core capability and pack in return-period details, fields, and units with no redundant wording. Every sentence 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 absence of an output schema, the description thoughtfully discloses the main return structure, content, and units. It doesn't address invalid coordinates or response edge cases, but for a simple read-only 2-parameter tool this is near-sufficient.

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 schema fully documents both lat and lon with ranges and examples, so the description's 'lat/lon' mention adds no new parameter semantics. With 100% schema coverage, the baseline 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 opening 'Get the 7-day NWS forecast' identifies a specific action and resource, and the clarifying details about ~14 day/night periods distinguish it clearly from hourly or zone-based forecast siblings. The tool's scope is 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 for point-based daily forecasts through '7-day' and 'lat/lon', but it does not explicitly state when to use this tool instead of nws_forecast_hourly, nws_zone_forecast, or nws_observation_latest. No exclusions or alternative guidance are provided.

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