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

Annotations already declare readOnlyHint, openWorldHint, and idempotentHint=false, but the description adds material context beyond them: $0.01 per-call pricing, USDC charging from a configured wallet, budget-cap enforcement, and an explicit third-party-data/not-instructions warning for injection safety. This is genuinely additive; it just omits return shape or error behavior.

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 the resource description front-loaded, followed by pricing and safety caveats. Dense and largely waste-free, though the parenthetical '(product ski.inventory)' is slightly redundant with the tool name.

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 paid, open-world read tool with no output schema, the description covers the essential context: what is returned, what it costs, how payment is charged, and that results are untrusted third-party data. Only the shape of the returned lift/run data is left unstated, a minor gap given no output schema is defined.

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 schema documents country, state (required for US), and confirm_over_cap in detail. The description adds no parameter-level meaning beyond the schema, 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?

The description states precisely what is returned: 'Lifts and runs of a ski area as mapped,' which is a concrete resource an agent can distinguish from generic lookups. It lacks an explicit verb and does not differentiate from close siblings such as ski_coverage, ski_operator, ski_resort, or ski_prices, so it falls short of a 5.

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?

There is no guidance on when to use this tool versus the many ski-related siblings (ski_coverage, ski_operator, ski_prices, ski_prices_bulk, ski_quote, ski_resort). The payment/budget caveats are cost conditions, not routing guidance, so the agent is left to infer the selection criteria.

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