Create a solid cylinder in Rhino by defining its base center, radius, and height. Control orientation with an optional axis and cap top and bottom as needed.
Add a cylinder; in standalone mode the axis must be world Z.
| 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 already signal a write operation (readOnlyHint=false), and the description's 'Add' is consistent with that. The description adds one genuinely useful behavioral fact — the axis is restricted to world Z in standalone mode — but does not disclose what happens if a non-Z axis is passed (error vs. silent coercion) or other 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?
A single front-loaded sentence with an active verb and zero filler; it is efficiently structured. It is almost too sparse, sacrificing parameter-level guidance for brevity, which caps the score below 5.
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 creation tool with three required parameters and several options, the description is thin: it covers only the axis restriction. It leaves 'standalone mode' undefined, offers no differentiation from rhino_cmd_cylinder/subd_cylinder siblings, and an output schema exists but does not excuse the missing guidance on 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?
With schema description coverage reported at 0%, the description must compensate, but it only adds meaning for one parameter (axis: must be world Z in standalone mode). Required parameters base_center, radius, and height, plus options like capped, layer, name, and doc_id, receive no explanatory treatment beyond their JSON names.
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 uses a specific verb + resource ('Add a cylinder'), and the annotations title 'Add Cylinder' reinforces it. However, it does not differentiate the tool from close siblings like rhino_cmd_cylinder, rhino_subd_cylinder, rhino_cone, or rhino_box, so an agent cannot tell why this variant exists.
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 given on when to choose this tool over alternatives; the sibling list is large but unaddressed. The only conditional note ('in standalone mode') is a constraint, not a routing rule, and 'standalone mode' itself is never defined.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.