cdek_postalcodes

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

No annotations are provided, so the description carries the full burden. It only states the endpoint and parameter, omitting any behavioral traits such as error handling, rate limits, or side effects. For a GET endpoint, minimal disclosure but still lacking context.

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 description is extremely concise: one sentence plus a parameter list. Every part is front-loaded and necessary, with no extraneous information. It efficiently communicates the tool's purpose and parameter.

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?

Given the output schema exists, the description adequately covers the input parameter. It could mention potential error scenarios (e.g., invalid city_code), but for a simple retrieval tool, it is sufficiently complete.

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 schema has 0% description coverage, and the description adds crucial meaning by explaining that city_code is a CDEK city code and referencing cdek_cities for lookup. This compensates well for the schema's lack of parameter descriptions.

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 states the tool returns postal codes of a city, mentions the API endpoint, and explains the required city_code parameter with a cross-reference to cdek_cities. This distinguishes it from sibling tools like cdek_cities or cdek_delivery_points.

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 explicitly instructs to use city_code from cdek_cities, providing a prerequisite. However, it does not discuss when not to use this tool or suggest alternatives among siblings, which is acceptable for a simple lookup tool.

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