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

With no annotations, the description fully discloses behavior: regulatory surcharges, incoterm adjustments, CIF insurance, duty/brokerage, financial carry, and conditional output (marginErosionPct only when unitSellingPrice is provided). It also lists exact return fields, making the tool's behavior highly transparent.

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, well-organized paragraph that front-loads the purpose, then explains calculation layers, then lists outputs, and ends with a critical parameter tip. Every sentence adds value and no information is wasted.

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?

The tool has 16 parameters, no output schema, and no annotations; the description compensates by explaining the full scope of calculations, conditional outputs, and return content. It provides enough context for an agent to invoke it correctly and interpret results, while parameter details are available in the schema.

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 must add parameter meaning. It explicitly explains baseDutyRate format ('Pass baseDutyRate as a decimal'), notes automatic surcharge application, and mentions incoterm types and destination-specific behavior. While not every parameter is elaborated, the most non-obvious ones are addressed and schema names carry the rest.

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 uses a specific verb ('Calculates') and clearly identifies the resource ('total landed cost per unit for a Shopify merchant importing goods'). This distinguishes it from sibling tools (inventory_health_score, quick_inventory_diagnosis), which are inventory-focused rather than cost-calculation-focused.

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 clearly states the context for use (importing goods with Shopify, applying regulatory and incoterm adjustments), but it does not explicitly mention when not to use it or name alternative tools. Since siblings are unrelated, this clear contextual framing earns a 4 rather than a 5.

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