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

With no annotations, the description carries the full burden. It discloses the returned content (ports, guide URL, export process, freight calculator), which implies a read-only lookup, but says nothing about permissions, freshness, or failure modes for an unknown country code.

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 sentences, front-loaded with the payload contents before the code hint, and neither sentence is padding. 'Official-style' is slightly vague, but the structure is otherwise efficient.

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 one-parameter, annotation-free lookup with no output schema, the description usefully substitutes for an output schema by listing what comes back. Only the read-only nature and unknown-code behavior are left implicit.

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% and the single countryCode parameter is already documented with ISO examples. The description's GB/BE note mostly restates the schema's own examples, adding only a light popularity hint, so the baseline 3 for full coverage applies.

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 a specific resource (import notes for a destination) and enumerates its content: ports, country guide URL, export process, and freight calculator. That is far more concrete than the bare name, though it never names a sibling tool to distinguish itself from estimate_shipping or list_destinations.

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 sentence about GB and BE is guidance on which country codes buyers use most, not on when this tool should be chosen over siblings. There is no explicit when-to-use or when-not-to-use condition, so usage remains implied.

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