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

The description adds valuable behavioral context beyond the readOnlyHint annotation by disclosing that it uses real 3D packing rather than simple volume math and reports the binding limit (dimension/weight/volume). It also clarifies the constraint that all cartons of a set must be in the same container, which is not evident from the schema.

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 concise and front-loaded, with five sentences that each contribute substantive information without redundancy. It efficiently communicates the core question, product concept, packing behavior, and default container behavior.

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 adequately covers the tool's logic and output (binding limit per container) for a complex tool with no output schema. However, it could be more explicit about the exact return format (e.g., a list of results per container) and how rotation/stacking flags affect results, but the given context is largely 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?

With 50% schema coverage, the description compensates by explaining the product/carton relationship (qtyPerSet) and the significance of the containers parameter (defaulting to standard container types). It adds meaning beyond the schema's field descriptions, though it does not detail every parameter like allowRotation or allowStacking.

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 tool's purpose with a specific verb ('fit') and resource ('container'), and elaborates on the concept of sets and carton types. It distinguishes itself from likely siblings by emphasizing real 3D packing and reporting the binding limit, which aligns with an estimation rather than actual packing tool.

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 provides clear context on when to use the tool (to estimate capacity in complete sets) and includes practical usage guidance like omitting containers to use standard container types. However, it does not explicitly name alternatives or state when not to use it, so it falls short of a full 5.

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