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

Annotations already declare readOnlyHint=true, destructiveHint=false, and openWorldHint=false, so the safety profile is fully covered. The description adds only a concrete computed example (cube side 5 → 125), which is mildly useful but discloses no behavior beyond the structured data.

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 with zero filler, and the supported-shape list is front-loaded. It is efficient, though the example sentence could have been spent on the per-shape parameter requirements instead.

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, so return values need not be explained, and safety is covered by annotations. However, with 7 parameters and additionalProperties=false, the definition never states which inputs each shape needs (e.g., sphere→radius, prism→base_area), leaving a real risk of malformed calls.

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 every parameter is already documented and the baseline is 3. The worked example hints at the shape→parameter mapping, but the description does not state which parameters each shape requires, adding little over 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?

The description names the resource (volume) and enumerates the supported shapes, so an agent can distinguish it from calculator_area, calculator_surface_area, and calculator_volume_convert. It stops short of explicitly naming those siblings as alternatives, which keeps it at 4 rather than 5.

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?

Usage is implied by the shape list and the worked example, but there is no explicit statement of when to use this versus calculator_volume_convert or calculator_geometry_3d. The agent must infer the routing from the tool name and shape enumeration alone.

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