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

With no annotations provided, the description carries the full burden of behavioral disclosure. It conveys only that the tool concerns surface area, but does not state whether the tool returns a numeric value, whether it assumes a side length, what the output format is, or that it is a pure calculation with no side effects.

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 extremely short and front-loaded, which is structurally concise. However, the 'Cube Surface:' prefix is redundant with the tool name, and the description is too sparse to serve as a genuinely useful definition for an agent.

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?

For a simple calculation tool, the description is minimally adequate in naming the operation, but it is incomplete given the lack of annotations, output schema, and any mention of how a side length is provided or what the result represents. An agent cannot confidently predict the tool's behavior from this definition alone.

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?

The input schema has zero parameters and schema description coverage is 100%, so there are no parameters for the description to clarify. Per the baseline for zero-parameter tools, this is adequate, though the description misses the opportunity to explain how the cube's dimensions are supplied or implied.

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 identifies the resource and metric — 'Surface area of a cube' — which is enough to infer the domain and distinguish it from cube-volume or cube-diagonal. However, it is a noun phrase rather than a clear verb-based statement of what the tool does, and it gives no indication of how the calculation is invoked or what input it requires.

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?

There is no guidance on when to use this tool versus the many related geometric tools such as cube-volume, cone-surface, or sphere-surface. The description relies entirely on the tool name for selection, providing no explicit context, conditions, or alternatives.

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