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

Annotations already mark this as readOnly and closed-world, so the description need not establish safety. It adds that the tool estimates rather than quotes, enumerates the charge categories, and covers bans, Incoterm payer, and exporting-country requirements, which usefully sets output expectations. It omits any accuracy, currency, or non-binding-disclaimer context.

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?

Three compact sentences, front-loaded with the core action and ending with a clear usage cue. No filler or repetition of schema fields.

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 complex 11-parameter estimator with nested items and no output schema, the description explains the high-level return categories but not the structure of results or key limitations. The schema carries most input detail, so it is serviceable, but the missing output/limits context leaves a 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?

Schema description coverage is 82%, so the schema already documents most inputs in detail. The description only broadly gestures at modes ('parcel or freight') and mentions Incoterm/bans, without adding syntax, defaults, or item-level meaning beyond the schema.

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?

Specific verb 'Estimate' and resource list (duties, tariffs, taxes, fees, bans, Incoterm payer) distinguish it from a generic quote tool. But it does not name or contrast with sibling border_lane_insights, border_rules_status, or door_cost_estimate, so sibling differentiation is absent.

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?

Provides a clear timing cue: use before buying from or shipping across the border. That frames the use case, but it gives no when-not conditions and never routes the agent to or away from the sibling tools.

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