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

Given the strong annotations (readOnly, idempotent, non-destructive), the description adds useful behavioral context: it returns only destinations/countries that have stays, includes stay counts, and enumerates collection categories. It does not contradict the annotations and provides meaningful semantics beyond them.

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 sentences with no filler. The description is front-loaded with the core purpose and then immediately adds the relationship to search_stays, earning every word.

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?

The output schema covers return values, annotations cover safety and idempotency, and the description covers the semantic purpose and downstream use in search_stays. Nothing essential 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?

Schema description coverage is 100% for the single optional country parameter, so the schema carries the parameter documentation. The description adds no additional meaning about the country filter, but the baseline of 3 is appropriate because the schema already fully explains it.

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 clearly identifies the resource (destinations and collections), the action (list), and the specific scope (those that have stays, with counts). It also explicitly names the sibling relationship to search_stays by stating that returned names and slugs are filters, which differentiates this from other list tools.

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 states an explicit use case: the returned names and slugs are the filters for search_stays. This effectively tells an agent when to call this tool, though it does not explicitly name alternatives or say when not to use it.

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