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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint=false. The description adds valuable behavioral context: the 18-markets-to-13-rule-sets mapping (six EU markets share one rule set) and the UK-label/GB-machine-code quirk. This goes beyond annotations and helps the agent interpret output nuances without contradicting them.

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 three sentences with the core action front-loaded after a brief rhetorical question. The UK/ISO note is a useful, non-redundant addition. The opening question is somewhat cosmetic but does not detract from clarity.

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 single-parameter, read-only resolver with an output schema provided, the description covers the mapping semantics and an important edge case (UK vs GB). It does not explicitly state when to invoke it or how invalid inputs are handled, but given the low complexity and existing annotations, these are not critical gaps.

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 0%, so the description carries the burden for explaining the single ship_to parameter. It provides six concrete example formats ('US', 'US-CA', 'UK', 'FR', 'EU-DE', 'JP'), which give a solid sense of accepted values, but it does not fully specify the allowed format, enumerate all markets, or describe invalid-input behavior. This is adequate but not exhaustive.

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 resolves a ship-to value into one of 18 markets and its associated rule set, with concrete examples. This is a specific verb-plus-resource statement that inherently distinguishes it from sibling resolve_actor, though it does not explicitly name any alternative.

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 implies when to use the tool—whenever a ship-to needs mapping to a market/rule set—but provides no explicit when-not-to-use instructions or comparisons to sibling tools such as get_market_status or resolve_actor. The context is clear, but exclusions and alternatives are absent.

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