Get Shipping Rates

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

Without annotations, the description carries the full burden. It discloses that the tool returns available service options with prices, transit times, and delivery guarantees. It does not explicitly state side-effect free behavior, but the get operation is inherently read-only. The description is sufficiently 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 three concise sentences. The first states the purpose, the second explains returns, and the third provides a usage hint and common codes. Front-loaded and no wasted words.

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?

Given the complexity (4 parameters, nested objects, no output schema), the description adequately covers the tool's functionality, return values, and a key usage nuance (omitting service code). The schema covers the rest, making the description complete.

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 input schema covers all parameters with descriptions (100% coverage, baseline 3). The description adds value by listing common service codes (03=Ground, etc.) and explaining the behavior of omitting the service code, which goes beyond baseline.

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 'Get shipping rates for a package between two addresses' and explains what it returns (service options, prices, transit times, delivery guarantees). It also provides common service codes, making the tool's purpose extremely clear and differentiating it from siblings like 'get_time_in_transit'.

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 implies usage by stating 'Omit the service code to get rates for ALL available services (shop rates)' but does not explicitly compare to alternatives or state when not to use. It provides clear context for using the tool, earning a 4.

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