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

Annotations declare readOnlyHint=true and openWorldHint=false, so safety is largely covered, but the description adds substantial behavior beyond that: it discloses the return payload (stable destination codes, public URLs, match method, scope, index release) and the ranking rules (containment precedence, unknown scope never assumed). It does not discuss result volume or pagination, which is a minor residual gap.

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 purpose and default behavior are front-loaded in the first two sentences, and each subsequent sentence carries a distinct operational fact (filter semantics, containment edge case, type semantics). The prose is dense and jargon-heavy, which costs some readability, but there is essentially no filler to cut.

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 an output schema present, the description need not detail return values, and annotations plus 100% schema coverage carry parameter definitions. The description fills the remaining hard parts — mode interaction, geography filter constraints, and cross-border containment behavior — so an agent has enough to call it correctly. Only pagination/volume expectations are unaddressed.

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 the baseline is 3, and the description does add genuine meaning above the schema: 'within' and 'types' filter canonical geography before ranking and require a geography-enabled release, and types are explicitly 'not population or city tiers'. Those clarifications are valuable but partial — 'limit' and 'language' get no treatment, and the mode interactions, while described, restate what the schema near-enum states.

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 opens with a specific verb and resource plus a dual scope: 'Search published destinations by name or traveler intent.' That is clearly distinct from a generic place lookup or a documentation search. It stops short of naming a sibling (e.g. search_places) to contrast against, so the differentiation is inferred rather than stated.

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?

There is strong guidance on choosing between the three modes ('mode defaults to auto', 'Explicit name never embeds', 'intent always searches by meaning'), which is real usage routing. However, there is no statement of when to use this tool instead of the other search or get_destination_* siblings, and no exclusions or prerequisites for calling it at all. Mode selection is covered; tool selection is left to inference.

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