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

With no annotations, the description carries the full burden. It correctly states the core outputs ('Returns dim weight kg') and inputs, but it fails to clarify the role of actual_kg (which is a required parameter) and references a 'divisor' that does not correspond to any input schema parameter, creating ambiguity about the tool's actual behavior.

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 short (3 sentences) and front-loaded with purpose, but it sacrifices accuracy for brevity by including a divisor that is not in the schema. It is concise but not fully clear, and every sentence earns its place except the misleading divisor remark.

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 presence of an output schema, return values need not be explained. However, the description fails to address the required actual_kg parameter and the missing divisor parameter, leaving the tool's behavior incomplete. The reference to list_bundles is peripheral and does not compensate for these gaps.

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 coverage is 100%, so baseline is 3. However, the description adds a 'divisor (5000 air, 6000 ground)' that is not an input parameter, which is misleading. It does not explain the role of actual_kg or how the divisor is applied, and the provided divisor values suggest a missing parameter. The description partially clarifies L×W×H but confuses with the extraneous divisor.

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 the verb 'Compute' and the resource 'volumetric (dimensional) weight for shipping'. It distinguishes itself by specifying the context of carrier billing and providing a reference to related calculators, making its purpose specific and distinct from siblings like calculate_international_shipping.

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 gives context about when this tool is relevant (shipping, carriers bill higher of actual/dim weight) and mentions list_bundles for related tools, but it does not explicitly state when to use this tool over alternatives or provide exclusions. The guidance is implied but not directive.

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