Rounds selected edges of a polysurface or solid to a specified radius. Use to create fillets on 3D geometry.
Fillet the selected edges of a polysurface or solid.
Args:
controller: RhinoController instance.
radius: Fillet radius.
Returns:
Dict with command result.
| Name | Required | Description | Default |
|---|---|---|---|
| radius | No |
| Name | Required | Description | Default |
|---|---|---|---|
| result | Yes |
Changes observed during successful MCP inspections.
v1.0.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
No annotations are provided, so the description carries the full burden of behavioral disclosure. It mentions the operation modifies selected edges and returns a dict, but it does not disclose prerequisites, side effects, failure modes, or whether the original geometry is altered. A fillet operation is a mutation, but this is only implicit.
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 short and front-loaded with the core purpose. The Args/Returns formatting is conventional and easy to scan, though the 'controller' line is unnecessary and slightly noisy for the actual schema.
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 one-parameter operation, the description identifies the target geometry and the core action, and an output schema is present. However, it omits practical invocation details such as whether edges must be selected before calling, what units the radius uses, and what the returned 'command result' contains.
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 schema has no parameter descriptions (coverage 0%), and the description only says 'radius: Fillet radius', which adds little beyond the property name 'Radius'. It does not explain units, valid ranges, or behavior for edge cases. The stray 'controller' argument in the docstring is also not part of the input schema and could confuse invocation.
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 action ('Fillet') and the resource ('selected edges of a polysurface or solid'), so an agent can understand the basic purpose. It does not explicitly differentiate this from siblings like rhino_variable_fillet or rhino_fillet_surface, though the 'selected edges' qualifier helps.
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 filleting already-selected edges on polysurfaces/solids, but it gives no explicit guidance about when to choose this over related tools such as variable fillet, chamfer edges, or fillet surface. The usage context is only implied by the operation name and target geometry.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.