rhino_create_ellipse

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

No annotations convey safety or behavior hints (all false), so the description carries the full burden. It only mentions creation, implying mutation, but does not disclose what happens with invalid radii, whether a plane is required, or how the object is added to the scene. Minimal behavioral disclosure.

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 a single concise sentence, which is easy to parse. However, it is too sparse, omitting important operational details that could be included in a similarly concise manner. It is brief but not optimally balanced with content.

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?

The tool has a nested object with six properties, and while an output schema exists, the description explains neither the creation context nor the behavior of optional parameters. For a creation tool with multiple coordinates and attributes, the description is inadequate for an agent to call it correctly without additional inference.

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 0% per context, so the description must compensate. It clarifies that the two radii are independent ('separate X and Y radii'), which adds meaning beyond the parameter names, but it completely ignores other parameters like center, normal, name, and layer. Insufficient compensation for the schema's lack of descriptions.

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 states the specific verb 'create' and resource 'ellipse', and the phrase 'separate X and Y radii' clearly distinguishes it from rhino_create_circle and other curve creation tools. It fully conveys the core purpose without ambiguity.

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?

No guidance is provided on when to use this tool over alternatives (e.g., circle vs. ellipse, or other creation tools). The description is a bare statement of action with no context about prerequisites, coordinate system assumptions, or typical scenarios.

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