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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, so the safety profile is fully covered. The description adds the sorting behavior (by SnowSure score, forecast, or recent snowfall) and the 'top-ranked' framing, which is useful context beyond the annotations. It doesn't disclose details like default limit or pagination, but the schema covers the limit parameter and the output schema exists, so a 3 is appropriate.

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 sentences with zero waste. The core action and resource are front-loaded, followed by the sorting behavior and example queries. 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?

For a read-only, idempotent list tool with a fully documented schema and an output schema, the description is nearly complete. It covers what the tool returns (top-ranked resorts by snow conditions), the sort options, and example use cases. It doesn't mention the default limit or max value, but the schema already documents those, so nothing critical is missing.

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 all three parameters (sort, limit, region) with descriptions. The description adds the notion of 'top-ranked resorts' and mentions the sort options, but it doesn't add meaning beyond what the schema provides. Baseline 3 is correct when the schema does the heavy lifting.

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 states a specific verb ('Get'), a clear resource ('global snow report'), and the key behavior (top-ranked resorts by snow conditions, sorted by SnowSure score, forecast, or recent snowfall). It also includes example user queries ('where has the best snow?', 'top ski resorts right now'), which helps an agent recognize when to invoke it. This clearly distinguishes it from siblings like get_my_snow_report or get_regional_summary.

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 explicit example queries that signal when to use this tool ('where has the best snow?' or 'top ski resorts right now'). It does not explicitly name alternatives or state when not to use it, but the query examples plus the global scope give clear context. Sibling tools like get_my_snow_report or get_regional_summary are implicitly differentiated by the global scope.

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