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

Annotations cover the safety profile (readOnlyHint=true, openWorldHint=false). The description adds genuinely useful behavior: results are *candidates* rather than a single answer, each includes a ready-to-paste `location` object, and the call is Free. It doesn't state result limits or ordering, keeping it short of a 5.

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?

Three short sentences, front-loaded with purpose, then return shape, then the optional narrowing parameter. Nothing is padded or redundant.

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 no output schema, the description correctly carries the return-value burden by explaining that candidates come back with a usable `location` object. Only ranking/tie-breaking or maximum-candidate behavior is left unspecified, a minor gap for a simple lookup.

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%, so the baseline is 3. The description restates the ISO alpha-2 format and adds that `country` 'narrows the search', which is a mild semantic gain over the schema's own wording, but it offers no new detail about matching behavior.

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 and resource ('find the place id of a city') plus the situational purpose ('for a listing's location'). This is clearly distinct from the sibling post/category tools, so an agent can route to it without opening the schema.

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 phrase 'for a listing's location' plus 'to paste into the listing' establishes when this tool is needed: resolving a location before creating/updating a listing. There are no explicit exclusions or named alternatives, but the context is unambiguous.

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