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

With no annotations, the description carries the behavioral burden. It discloses that the tool provides prohibited-item data and that it should be shown before booking, but it does not mention return structure, read-only nature, or potential error/empty-list behavior. This is adequate but not rich.

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 a single sentence with two concise clauses. It front-loads the core content (prohibited items) and then adds a direct usage instruction. Every word earns its place, with no redundancy.

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 zero-parameter tool with no output schema, the description covers the key aspects: domain (EuroCollis and Morocco/EU customs), content (prohibited items), and application context (surface before booking). It does not specify the output format, but the simple nature of the lookup makes this a minor gap.

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 tool has zero parameters, and the baseline for 0-parameter tools is 4. The description correctly adds no parameter details because none are needed; the schema already confirms an empty parameter set.

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 identifies the tool's subject—prohibited items for EuroCollis and Morocco/EU customs—and conveys a retrieval action through the phrase 'Items ... prohibit'. It differentiates from siblings by being specifically scoped to prohibited-items data, though it does not use an explicit verb like 'retrieves' or 'lists'.

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 instruction 'Always surface before a booking recommendation' explicitly states when this tool should be used, providing clear context for an agent. It does not mention alternatives or exclusions, but the timing guidance is actionable and sufficient for this tool.

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