Справочник регионов

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

readOnlyHint and openWorldHint already declare the safe, external-read nature, so the safety profile is covered. The description adds useful domain facts beyond annotations — the magic code 225 = Россия and that with_parents distinguishes same-named cities — but return/pagination behavior is left to be inferred.

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, front-loaded fragments with no filler: resource first, then filter hint, then the with_parents behavior. Efficient and easy to scan, though telegraphic rather than fully structured.

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 read-only reference lookup with 100% schema coverage and no output schema, the description supplies enough context (what the regions are, the key code, the special with_parents toggle). Nothing essential to a correct call is missing, though a note on result shape would round it out.

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 all three parameters are already documented in the schema, making 3 the baseline. The description largely restates the with_parents semantics already present in the schema; the 225 = Россия fact is extra context but not tied to a specific parameter.

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 names the resource concretely — a reference of region codes (GeoRegions) — and frames its purpose (для таргетинга), so an agent knows this is a lookup tool rather than a campaign mutator. It does not explicitly contrast itself with any sibling, but the resource is clear enough to disambiguate from the surrounding campaign 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?

Usage is only implied: 'для таргетинга' and 'Фильтр по названию' suggest when the tool is relevant, but there is no explicit when-to-use/when-not and no named alternative (e.g. get_time_targeting or get_campaign). Adequate but leaves the agent to infer the trigger conditions.

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