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

Annotations already cover safety (readOnlyHint, openWorldHint, idempotentHint=false), and the description adds real value beyond them: explicit per-call pricing (product ski.resort, $0.01), USDC wallet charging subject to budget caps, and a prompt-injection warning that results are third-party data, not instructions. This is meaningful behavioral context, though it does not cover failure modes or refund 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, front-loaded with what the tool returns before moving to cost and trust caveats. Slightly list-heavy but every sentence earns its place; no filler.

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 hints at return content (lifts, runs, altitude, season, links), and it covers the payment model and the third-party-data caveat an agent needs before calling. Nothing critical is missing for a read-only single-record lookup.

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%, including a detailed explanation of confirm_over_cap, so the schema carries parameter meaning on its own. The description adds nothing parameter-specific, making the baseline 3 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?

States a specific resource ('one ski resort') and enumerates the payload ('lifts, runs, altitude, season and links'), which lets an agent see this is a descriptive profile rather than a price/inventory lookup. It does not explicitly contrast itself against close siblings like ski_coverage or ski_operator, 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?

The description establishes the cost and payment context, which implicitly frames it as a single paid lookup, but never says when to prefer this over ski_coverage, ski_operator or ski_prices_bulk. Usage is inferable from the singular 'one ski resort' scope but not spelled out.

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