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

Annotations already declare a safe, idempotent, non-destructive read, so the safety profile needs no restating. The description adds genuinely useful context by stating the result is "volume in input-units cubed," but says nothing about precision, shape-specific required dimensions, or validation 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?

Front-loaded with the verb and resource, then use cases, then I/O, then a cross-reference. Four short sentences with no padding; only the trailing bundle pointer is of marginal value.

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-value documentation is not required, and annotations cover safety. The remaining gap is that neither schema nor description explains the shape-to-dimension mapping, which an agent needs to call correctly for cone, prism, or pyramid.

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 nominally 100%, so the baseline is 3, and the description only repeats "Inputs: shape + dimensions" without explaining which dimensions apply to which shape (e.g., radius for sphere, base_area for prism). It lists a subset of the enum shapes but adds no mapping to the dimension parameters.

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 verb (Compute) and resource (volume for 3D shapes) and enumerates the supported shapes, so the core purpose is unambiguous. However, numerous siblings (calculate_cone, calculate_cylinder, calculate_sphere, calculate_pyramid, calculate_pool_volume, calculate_aquarium_volume) overlap directly, and the description makes no attempt to differentiate from them.

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?

"Use for geometry, packaging, or construction" gives implied usage contexts, but there is no explicit when-to-use versus the dedicated per-shape siblings. Pointing to list_bundles for "related 'math' calculators" is a weak routing hint rather than an alternative-selection rule.

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