Bevel selected edges of a mesh object in Blender. Control bevel width and segment count to create rounded or flat chamfers.
Bevel selected edges of a mesh.
Args: object_name: Object name. width: Bevel width. segments: Number of segments (1 = flat bevel).
| Name | Required | Description | Default |
|---|---|---|---|
| width | No | ||
| segments | No | ||
| object_name | Yes |
Changes observed during successful MCP inspections.
v3.0.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations, the description carries the full burden of behavioral disclosure, but it only restates the action and parameters. It does not disclose whether the bevel is destructive, requires edit mode, or modifies the existing geometry in place.
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 compact, front-loads the operation, and uses a clean Args block. Every line contributes either to the tool's purpose or to parameter understanding, with no filler.
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 mutation tool with no annotations and no output schema, important context is missing: how edges are selected, whether the object must be in edit mode, units for width, and what the tool returns. An agent cannot fully predict the tool's requirements or side effects.
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%, so the description partially compensates by naming all three parameters. However, 'object_name: Object name' and 'width: Bevel width' largely repeat the schema titles; only 'segments (1 = flat bevel)' adds meaningful semantic value.
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 first sentence uses a specific verb ('bevel') and resource ('selected edges of a mesh'), making the tool's operation immediately clear. The name is not merely restated, and the scope is narrow enough to distinguish it from broad edge-editing siblings like edit_mesh_edges.
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 statement of when to use this tool versus alternatives, no prerequisites, and no mention that edges must be selected beforehand. Despite sibling tools like edit_mesh_edges or apply_modifier, the description never addresses which workflow should call this tool.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.