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

Annotations already declare the full safety profile (readOnly, idempotent, non-destructive, closed-world), so the bar is lower. The only added behavioral nuance is the 'have restaurants' scoping filter, with no mention of ordering, pagination, or result completeness.

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?

A single efficient sentence with the resource and scope front-loaded, and no filler. It is appropriately sized, though almost too terse to carry much information.

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 zero-parameter tool with annotations covering safety and no output schema, the description is minimally adequate. It omits return shape, ordering, and whether the list is exhaustive or paginated, which an agent might want before invoking it.

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 tool takes zero parameters, so the baseline of 4 applies. There are no parameters whose semantics the description could meaningfully add.

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 ('List') and concrete resources (countries, regions, cities), and adds a scope constraint ('that have restaurants'). It is clearly distinguishable from get_listing/get_stats, though it doesn't explicitly contrast with the similar-looking list_categories/list_sources siblings.

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 gives no when-to-use context, prerequisites, or relationships to alternatives like search_listings or list_categories. An agent gets no signal about when this tool is the right choice versus the other listing tools.

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