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

Annotations already declare readOnlyHint, openWorldHint, and idempotentHint, so the safety profile is covered. The description adds cost context ('FREE.') and the response shape (resort ids), which are genuinely beyond the structured fields, though pagination or unfiltered behavior is unstated.

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 short sentences with the cost flag front-loaded and zero filler. It is efficient, though the second sentence is dense enough that its clause structure requires a re-read.

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, zero-required-parameter discovery tool with a fully documented schema, the description covers what it returns, what it costs, and how to scope it. The main omission is what happens when country is omitted.

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 single optional parameter is documented with an example ('Austria' or 'at'). The description merely says 'by country', adding no syntax or default-behavior detail beyond the schema, so the baseline 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 resource (ski resorts with lift-ticket prices) and a scoping dimension (by country), and names the downstream id space for ski_prices and trip_map. It does not explicitly differentiate from close siblings like ski_inventory or ski_resort, 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?

'With country, lists the resort ids for ski_prices and trip_map' implies the discovery use case, but never states when to prefer this over ski_inventory, ski_resort, or the price tools directly. Usage is inferable rather than spelled out.

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