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

Goes well beyond the readOnlyHint/openWorldHint annotations: it specifies the return contract (per-container placements with x,y,z in cm, load ordering, volume utilization, weight, weightBalance object, unplaced pieces) and notes that weightBalance applies only to bulk loads and that unbalanced loads get flagged. It also warns that placement order respects support relationships and rear-to-door sequencing, which an agent could not infer otherwise.

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?

Front-loaded with the action and modes, then the return shape; every clause carries information. The single long paragraph is dense and the returns list is run-on, but nothing is filler.

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?

With no output schema, the description does the heavy lifting on return values, which is the main burden for a complex nested-input tool. Remaining gap is that the container/containers relationship and options defaults are not explained, so an agent could mis-set maxContainers or the single-container field.

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 only 33%, and the description compensates for some of it by explaining loadingMode, pallet, orientations, noOverstack/noUnderstack and loadingOrder semantics. But it is silent on the `container` vs `containers` fields and the `options` object (deepOptimize, maxContainers, loadingDirection) entirely, so half the top-level surface is undocumented in both places.

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?

States a specific verb+resource ('Pack a list of cargo SKUs into one or more shipping containers') and names the solver, then immediately distinguishes the two operational modes (bulk vs pallet). An agent can tell exactly what this does versus estimate_capacity without reading the schema.

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?

Clearly explains when each mode applies ('bulk' loads cartons straight in, 'pallet' stacks onto pallets first and 'requires the `pallet` field'), which is real routing guidance. However, it never mentions the sibling tools (estimate_capacity) or when to prefer a capacity estimate over a full pack, so exclusions are absent.

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