calculate_international_shipping

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

The description indicates it returns cost range and lead time, implying it is an estimation tool. However, without annotations, it does not disclose whether it is idempotent, read-only, or makes external calls.

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 three sentences long and covers purpose, use cases, and inputs/outputs, but the inaccuracies and redundancy prevent it from being highly effective.

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?

With an output schema present, the description adequately mentions return values, but it fails to explain the from_zone parameter correctly and omits the fact that countries are replaced by zones, leaving gaps for an agent.

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?

Although schema coverage is 100% with descriptions, the tool description adds misleading info (from-country, to-country, carrier) that does not align with the actual parameters (only from_zone with zones). This reduces clarity.

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 states it estimates international shipping cost and delivery time, which distinguishes it from other calculate tools. However, it mentions parameters like 'carrier' and 'to-country' that do not match the schema, creating minor confusion.

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?

It suggests using for e-commerce or expat shipping and directs to list_bundles for related tools, but lacks explicit guidance on when not to use or alternatives beyond that.

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