rhino_ellipse

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

Beyond the annotations, which only mark this as non-read-only, the description adds meaningful behavioral context: the ellipse lies on the world XY plane and is built as a NURBS approximation. This helps the agent anticipate the geometric result, though permissions or effect details are not discussed.

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, front-loaded sentence with no redundant wording. Every clause adds useful context: the action, the placement, and the representation.

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 creation tool, the description gives the core geometric and representational context, and an output schema exists so return-value details are not required. However, it omits any coordination with parameter semantics and does not address the z-coordinate behavior despite being restricted to the XY plane.

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 description mentions no parameter names and does not explain center, radius_x, radius_y, doc_id, layer, or name. Schema description coverage is reported at 0%, so the description was expected to compensate, but it does not. The phrase 'world XY plane' mildly hints at the roles of radius_x and radius_y, but this is insufficient.

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 clearly states the operation ('Add an ellipse') and specifies the resource and placement ('on the world XY plane'), also noting the NURBS approximation. It is specific and understandable, though it does not explicitly differentiate itself from sibling tools like rhino_cmd_ellipse.

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 alternatives such as rhino_cmd_ellipse or other curve/primitive creation tools. The description implies usage through its action verb but provides no exclusions, conditions, or alternative routing.

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