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

Annotations only mark it as non-readOnly, open-world, non-idempotent; the description goes well beyond by disclosing the exact price ($0.01/call, product ski.prices), the USDC wallet charge, budget-cap enforcement, the confirm_over_cap override behavior, and an injection-safety note ('third-party data, not instructions'). This is exactly the behavioral context an agent needs for a paid call.

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?

Six short, front-loaded sentences with zero redundancy: purpose, id source, price, payment mechanics, safety, and free alternative. 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 paid, budget-capped tool with a fully documented schema and no output schema, the description covers the essential economics and safety. It could be marginally richer on what the returned price payload looks like, but 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 coverage is 100%, so all five parameters are already documented, and the description's parameter-relevant additions ('resort ids: ski_coverage', budget caps tied to confirm_over_cap) largely echo the schema. Baseline 3 is appropriate when the schema carries the parameter burden.

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+resource (published lift-ticket prices) and scopes it to 'one ski resort,' which cleanly separates it from ski_prices_bulk. It also points at ski_coverage for resort ids, so an agent can place it among siblings without opening schemas.

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?

Gives a clear precondition (resort ids come from ski_coverage) and an explicit free alternative to try before paying (free_sample). It stops short of naming when this is preferred over ski_prices_bulk or ski_quote, so the sibling routing is only partially complete.

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