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

The annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, so the safety profile is clear. The description adds that it computes weight and item breakdown, but it does not disclose behavioral details such as the priority of saleId over productIds (which is only in the schema) or what happens when multiple inputs are provided. This is adequate but not rich.

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 two sentences long, front-loaded with the primary purpose, and contains zero filler. Every word contributes to understanding what the tool does and what inputs it accepts.

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?

The description provides a high-level output (weight and item breakdown) and lists the input alternatives. However, it lacks clarity on how the inputs interact (e.g., what if saleId and productIds are both provided? The schema says saleId takes priority but the description omits this). Given there is no output schema, a bit more detail about the output structure would improve completeness.

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 schema description coverage is 100%, with each parameter already well-documented (e.g., saleId takes priority, productIds assumes qty=1). The description merely lists the parameter names without adding new meaning or usage details beyond the schema, so it does not compensate above the 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 uses a specific verb ('Computes') and clearly identifies the resource ('shipment weight and item breakdown for a package'). It also enumerates the accepted inputs, making the tool's function unambiguous and distinct from the sibling tools, none of which compute package profiles.

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 statement 'Accepts a saleId, a list of productIds, or an explicit weightGramsOverride' provides clear context on when to use the tool (when you need a package profile and have one of these inputs). However, it does not explicitly mention exclusions or alternatives, so the score is below 5 but above 3.

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