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

Annotations already establish read-only, idempotent, non-destructive behavior. The description adds important behavioral context beyond annotations: the all-or-nothing refusal when any line cannot be read, and the fact that the response lists transport categories when packing_group is needed. It does not describe rate limits or detailed response structure, but it significantly improves transparency.

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 compact and front-loaded: it states what is calculated, the decision threshold, coverage, refusal behavior, and the packing_group requirement in only a few sentences. No sentence feels 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?

For a single-parameter computational tool with no output schema, the description covers purpose, scope, failure behavior, and the main conditional input requirement. It could go further in explaining the output fields, but it provides enough context for an agent to invoke the tool correctly.

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 100%, and the schema already documents lines, UN numbers, package counts, packing groups, and quantity per package. The description reinforces the packing_group condition but adds little syntax or format detail beyond the schema, so baseline 3 is appropriate.

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 and resource: total ADR 1.1.3.6 points for a vehicle load and determine whether the small-load exemption applies. It also scopes the tool to 92 UN numbers and names related concepts like transport category and packing group, making it distinguishable from sibling tools such as un_number_packaging.

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 explains the context in which the tool is used: vehicle loads, small-load exemption checking, and cases where packing_group is required. It does not explicitly name alternative sibling tools or when-not-to-use cases, so it falls short of full routing guidance.

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