Create a vertex group and optionally assign vertices with a weight, enabling targeted control for deformation and animation in Blender.
Create a vertex group, optionally assigning vertices with a weight.
| Name | Required | Description | Default |
|---|---|---|---|
| name | Yes | ||
| object | Yes | ||
| weight | No | ||
| vertices | No |
| Name | Required | Description | Default |
|---|---|---|---|
No arguments | |||
Changes observed during successful MCP inspections.
v0.1.0+hardened.2Does 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 states the obvious creation action and optional vertex assignment. It does not explain what happens if the group already exists, whether the object must already exist, or how the weight is applied to the listed vertices.
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 with no wasted words. However, conciseness is achieved by omitting important parameter context, so it is efficient but incomplete.
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 4-parameter creation tool with no annotations and zero schema description coverage, this description is under-specified. It fails to mention the required 'object' parameter, gives no usage context, and leaves the weight semantics ambiguous. The presence of an output schema does not compensate for these gaps.
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 must compensate, but it only lightly covers vertices and weight while omitting the required 'object' parameter entirely. It does not clarify that 'weight' is a single scalar applied to all assigned vertices or how the 'vertices' array relates to the object.
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 and resource, 'Create a vertex group', and notes the optional assignment of vertices with a weight. It is clear about the basic operation, though it does not explicitly differentiate itself from siblings like assign_vertex_weights or get_vertex_groups.
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 assign_vertex_weights or get_vertex_groups. No context is provided about prerequisites or whether this should be used before other vertex-group operations.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.