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

Annotations already mark the tool as read-only (readOnlyHint: true) and non-destructive (destructiveHint: false). The description goes beyond that by disclosing the maximum result count (up to 20 matches), the absence of pagination/bulk access, and that the returned slug is the identifier used by every other tool. This adds meaningful behavioral context about limitations and how the tool fits into the larger workflow.

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?

The description is compact and front-loaded: the purpose is stated in the first sentence, followed by the key return values and a limitation. No redundant wording. Every sentence adds value, and the structure helps an agent quickly grasp what the tool does and how to use it.

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 search tool with three simple optional parameters and no output schema, the description covers all essential aspects: what it takes (name/country), what it returns (slug, elevations, 3-day snow), the maximum result cap, and the absence of bulk access. The safety profile is already handled by annotations. Nothing critical is missing for an agent to call this tool correctly.

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?

The input schema has zero description coverage, so the description must compensate. It explains that 'query' is the resort name and 'country' is an ISO-2 country code. The 'limit' parameter is implied by the statement 'Returns up to 20 matches', though the description does not explicitly tie the parameter to that limit. Still, agents can reasonably infer that limit controls the number of results. This addition is useful beyond the bare schema.

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 ('find'), a clear resource ('European ski resorts'), and the two search dimensions (name and ISO-2 country code). It also specifies the output (slug, elevations, 3-day snow) and distinguishes itself from sibling lookup tools by noting that the slug is the ID every other tool takes. This makes the tool's purpose unambiguous and differentiates it from nearby tools like where_to_ski or plan_trip.

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 clearly indicates when to use the tool — to search resorts by name or country. It also gives operational guidance: refine the query rather than paging, since there is no bulk catalogue access. It does not explicitly mention alternatives or when not to use it, but the context of siblings implies that this is the primary lookup tool and that other tools consume its output. This is clear context without exclusions.

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