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

The description adds meaningful behavior beyond the readOnlyHint annotation: it discloses the composite data layers, output fields, coverage across ~3,200 counties, and 'Updates: on source cadence.' It does not cover rate limits or errors, but the added context is 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 front-loaded with the core return statement, then use cases, then update cadence. It is dense but every sentence adds value. The 'Updates: on source cadence' phrase is slightly cryptic, but the overall length is appropriate.

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?

Despite lacking an output schema, the description explains the return fields, data sources, geographic scope, and typical use cases. The only minor gap is how a specific county is selected, but since no county parameter exists, it implies county-level results are returned for all counties.

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%, and the 'days' parameter is fully described in the input schema, including tier requirements. The tool description does not add parameter-specific semantics beyond the schema, so the baseline score 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 clearly states the tool returns a 0-100 county weather-severity index, naming five specific component layers and the output fields. It distinguishes itself from siblings by focusing on a composite weather/climate risk score and explicitly describes its construction from AlpineDataWorks V2 layers.

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 gives explicit when-to-use guidance: 'Call when the user asks how abnormal, severe, or changing local weather or climate risk is' and for property, insurance, site-selection, or relocation decisions. It does not name alternative tools or provide exclusion criteria, so it misses the top score.

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