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

Beyond the readOnlyHint=true / openWorldHint=true annotations, the description discloses the upstream source (European Commission Access2Markets), that the answer includes the national plant health authority and applicable laws, and precise billing semantics: $0.002 USDC per successful call via x402, failures not charged. It omits anything about data freshness or how current the cited legal annexes are, which matters for a regulatory lookup.

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 scope and output are front-loaded and every clause (jurisdiction limit, regulator, price) carries information. The first sentence is a long run-on with stacked parentheticals and citations, which slightly impairs fast scanning but does not waste words.

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 three-parameter regulatory lookup with an output schema and annotations already present, the description covers scope, source, jurisdiction limit, and cost — enough for an agent to call it correctly. The remaining gap is freshness/versioning of the cited legislation, which an agent evaluating trustworthiness would want.

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 coverage is 100%: each of code, origin and destination already carries a description with an example, and the default destination (DE) is documented in the schema. The description only restates that the lookup is keyed on code and origin, adding no format or padding rules beyond what the schema provides, so the baseline 3 is appropriate.

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 precise determination ('whether an import ... falls under EU plant health control') plus the secondary output (other SPS/technical requirements), scoped to a 10-digit CN/TARIC code and origin country, citing the governing regulations. It is clearly distinct from neighbours like logistics_veterinary_border_control or logistics_eu_taric_consultation by domain, though it never names an alternative to make the contrast explicit.

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?

'EU imports only' is an explicit exclusion, and the description specifies the required inputs (CN/TARIC code + non-EU origin) so the agent knows the call shape. It does not, however, point to sibling tools for adjacent questions such as duty calculation or veterinary border checks, so routing guidance stops short of the full when/when-not/alternative pattern.

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