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

Annotations already establish that this is a read-only, non-destructive, non-open-world calculation. The description adds the supported shape set and a worked example, but gives no further behavioral context such as required parameter combinations per shape or error behavior.

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?

Two short sentences, front-loaded with the supported shape scope and followed by a compact example. There is no wasted text.

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?

An output schema exists, annotations cover the safety profile, and the schema documents all parameters. The description is largely sufficient, though it could more explicitly map required dimensions to each shape for a six-parameter 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 100%, so the schema already documents every parameter. The example 'cube side 5 → 150' adds a useful concrete mapping, but the description does not explain which dimensions apply to which shapes beyond that single cube case.

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 the specific resource (surface area) and the supported shapes: cube, cuboid, sphere, cylinder, cone. It is clear what the tool computes, but it does not differentiate itself from nearby siblings such as calculator_area, calculator_geometry_3d, or calculator_volume.

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 shape list implies when the tool is applicable, but there is no explicit guidance on when to use this versus calculator_area, calculator_geometry_3d, or calculator_volume. No exclusions or alternative-selection advice are provided.

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