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

Annotations already declare readOnlyHint=true, openWorldHint=false and destructiveHint=false, so the safety profile is fully covered structurally. The description adds no behavioral context beyond that: no mention that it is a pure deterministic computation, no error behavior for mismatched shape/dimension combinations, no units handling.

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?

A single front-loaded fragment that names the outputs and then the valid shapes; every token carries information and nothing is buried. It reads as a terse terse label rather than a sentence, but that suits a simple calculator.

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 an output schema present, return format needn't be described, and the 100%-covered input schema documents the per-shape dimensions. The one remaining gap is that the description does not say which dimensions are required for which shape, though the schema largely compensates.

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 100%, with per-field descriptions naming which shape each dimension belongs to (cube side, cuboid width/length, prism base area) plus enums for shape and calculation in the examples. The description only repeats the shape list and the surface_area/volume distinction, adding no syntax or conditional-requirement detail beyond the schema.

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 resource (3D shapes) and the quantities computed (surface area and/or volume), and enumerates the supported shapes: cube, cuboid, sphere, cylinder, cone, prism. It implicitly separates itself from the 2D-oriented siblings calculator_surface_area and calculator_area by scoping to 3D solids, but it never names those siblings explicitly.

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 usage (use this for 3D solids, not polygons or rectangles), but there is no explicit when-to-use or when-not guidance. Given siblings calculator_surface_area and calculator_volume exist, an agent gets only an indirect signal about routing.

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