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

Annotations already declare readOnly, idempotent, non-destructive, and closed-world, so safety is covered. The description adds genuinely useful behavioral context beyond that: exactly which metrics come back (24h, 7-day, next-7-day forecast, season totals) and the presence of a canonical page URL for citation.

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?

A single dense sentence with the resource scope front-loaded and the return payload following immediately. No filler, no repetition of the title.

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?

With no output schema, the description carries the return-value burden and does so well by naming the metrics and the citation URL. It leaves minor gaps: behavior for an unknown/unsupported code and whether the result is empty for states with no tracked resorts.

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 100% and the sole parameter's description already gives the two-letter format and examples (CO, NY, BC). The description restates 'two-letter code' without adding format, validation, or error behavior beyond what the schema provides, so the baseline of 3 applies.

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?

States a specific verb and resource ('every tracked resort in a US state or Canadian province') and enumerates the returned metrics, so the scope is unmistakable. It does not, however, distinguish itself from the sibling get_region_snow, leaving the state-vs-region boundary for the agent to infer.

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?

Usage is implied by the aggregation scope: reach for this when you want all resorts in one state/province rather than a single resort. There is no explicit when-to-use, when-not, or named alternative (get_region_snow, get_resort_snow) to route the agent.

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