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

Annotations already declare readOnly, idempotent, non-destructive, and closed-world behavior. The description adds useful scope and behavior context: it tests 90-degree rotation when allowed, treats all dimensions as the same unit, and explicitly disclaims 3D packing and safety certification. It does not contradict annotations and enriches understanding of what the calculation does and does not do.

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 three sentences, front-loaded with the core purpose, and every sentence adds distinct value: scope, unit constraint, rotation behavior, and exclusions. There is no filler or redundancy.

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 and low schema description coverage, the description should carry more burden. It omits any explanation of return values, layout output format, or parameter roles, leaving an agent without enough information to interpret results or fully understand inputs. Annotations cover safety aspects, but the description is not complete enough for this calculation tool.

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 only 13% (only 'gap' has a description). The description adds a helpful unit-consistency note ('All dimensions use the same unit') but does not map parameters to their roles (case vs item dimensions), explain the 'rotate' flag, or clarify any other parameter beyond what the intuitive names suggest. Given the low coverage, the description should compensate more than it does.

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 states a specific verb (calculate) and resource (uniform single-layer rectangular layout for toy footprints inside a display case), and explicitly rules out 3D packing and safety/load certification. This makes the tool's purpose unambiguous and distinguishes it from any generic packing tool, even though the listed siblings are unrelated.

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 implies when to use the tool (for single-layer rectangular display layouts) and gives a clear exclusion ('not 3D packing or a safety/load certification'), but it does not name alternatives or state a positive trigger condition. Usage is therefore inferred from the purpose statement rather than explicitly guided.

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