Create a tapered spiral NURBS curve in Rhino by specifying center, start/end radii, pitch, turns, and sampling density. Use it for precise spiral geometry in 3D models.
Add a tapered spiral sampled into a NURBS curve.
| Name | Required | Description | Default |
|---|---|---|---|
| args | Yes |
| Name | Required | Description | Default |
|---|---|---|---|
No arguments | |||
Changes observed during successful MCP inspections.
v1.0.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations include readOnlyHint=false, confirming this is a creation operation, but the description adds little beyond that. It does not disclose behavior such as where the curve is added (active document by default), whether existing geometry is affected, how the NURBS curve is constructed or sampled, or any side effects like creating a layer if specified. The name and definition field 'sampled into' hints at the conversion process, but this is not elaborated.
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 that front-loads the core purpose without unnecessary words. It could add more useful detail, but as written it is efficient and directly readable.
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?
With an output schema present, return values may be documented, but the description still lacks context about the relationship of this tool to similar curve/spiral tools, how the 'sampled' NURBS conversion works, and what happens when parameters like layer or doc_id are omitted. Given 0% schema coverage and no parameter explanations, this definition is inadequate for an agent to correctly configure all required inputs.
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%, meaning the schema alone does not explain most parameters. The description mentions 'tapered spiral' which maps to start_radius and end_radius, and 'sampled' maps to points_per_turn, but it does not explain pitch, turns, center, or the meaning of the required arguments. The description must compensate for the total lack of parameter descriptions but fails to do so for most fields.
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 'Add a tapered spiral sampled into a NURBS curve' clearly states the verb (add), the resource (tapered spiral), and the output form (NURBS curve). It distinguishes this from generic curve creation tools by highlighting the tapered spiral nature, though it doesn't explicitly contrast with siblings like rhino_helix or rhino_cmd_spiral.
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?
The description implies the tool is for creating a tapered spiral as a NURBS curve, which gives context for when to use it. However, it does not explicitly state when to prefer this over alternatives such as rhino_helix, rhino_curve, or rhino_cmd_spiral, nor does it mention any exclusions or prerequisites.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.