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

Beyond the readOnly and idempotent annotations, it adds important behavior: invalid input returns an error object instead of raising a protocol error, results are not proven optimal, and retrying after correction is safe. This gives an agent actionable expectations beyond what annotations alone provide.

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 denser but each section earns its place: capacity, example, output shape, use cases, algorithm caveat, error behavior, and retry safety. The read-only/idempotent sentence slightly repeats annotations, but it also adds practical retry guidance, so the cost is minor.

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?

It covers capacity limits, typical input, returned shape, intended use, algorithmic limitations, error handling, and idempotency. Given the schema and annotations, an agent has what it needs to select this tool and invoke it correctly without obvious 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?

The schema already covers all three parameters, so the baseline is 3. The description adds a concrete JSON example showing how to structure items and containers, which helps construct a valid call. It does not discuss the rules parameter in detail, but the schema already documents it.

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 identifies this as a bin-packing tool via 'Same packer as pack_bins' and clarifies the larger scale with 'up to 300 item units and 200 containers.' Its typical input and output shape make the resource and result clear, but the core action is expressed through comparison to pack_bins rather than an explicit 'packs items into containers' statement.

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?

It gives clear selection context: use this for order consolidation and load planning, and the capacity bound differentiates it from pack_bins. It does not explicitly state when not to use it or name a smaller-input alternative, though the capacity phrasing implies the boundary.

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