Itu Zones Codes For

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

With no annotations, the description carries the full behavioral burden. It does disclose a non-obvious trait — that IARU-split entities return each zone with the IARU's boundary wording — which goes beyond the schema, but it says nothing about error behavior for unknown codes, casing/format handling, or whether results can be empty.

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?

Two tight sentences with zero padding; the primary scope statement is front-loaded and the second sentence adds genuinely new information about IARU boundary handling.

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 two-parameter read-only query with an output schema (so return shape needn't be described) and full schema coverage, the description covers what the tool does and one subtle return behavior. The only meaningful omission is routing guidance against its near-identical siblings.

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 both parameters (dxcc, subdivision) are already fully documented in the schema. The description's phrase 'ADIF DXCC entity, or one of its subdivisions' restates that structure rather than adding syntax, format, or edge-case meaning.

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 states a specific resource and outcome — 'which ITU zones cover an ADIF DXCC entity, or one of its subdivisions' — so an agent knows exactly what it returns. It does not, however, differentiate itself from close siblings like itu_zones_lookup or itu_zones_search, which sound like they answer adjacent questions.

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 implied: you call it when you have a DXCC entity or subdivision code and want its covering zones. But no explicit when-to-use, when-not-to-use, or alternative tool is named, and with four similarly named itu_zones_* siblings that omission is a real gap.

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