Assigns specific vertices to a bone's vertex group with a defined weight, enabling precise control over character deformation and skinning.
Assign vertex weights to a bone's vertex group.
| Name | Required | Description | Default |
|---|---|---|---|
| bone | Yes | ||
| object | Yes | ||
| weight | No | ||
| vertices | Yes |
| 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 provided, the description carries full burden for behavioral disclosure. It only states the action, not whether it overwrites existing weights, the weight range, or any error conditions. No side effects or reversibility are mentioned.
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, but it is under-specified rather than efficiently structured. It lacks any breakdown of parameters or usage context, so while concise, it fails to provide actionable structure.
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 tool with 4 parameters (3 required) and no schema descriptions, this description is grossly incomplete. It omits how to specify the object and bone, what the vertices array means, and the expected weight range. The presence of an output schema doesn't compensate for the lack of input guidance.
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%, and the description adds no meaning beyond the schema. It does not explain that 'object' refers to the mesh, 'bone' is a bone name, 'vertices' are indices, or that 'weight' has a default of 1. The agent is left without any semantic guidance.
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 (assign vertex weights) and the resource (a bone's vertex group), which distinguishes it from siblings like set_vertices or create_vertex_group. However, it lacks specificity about the context (e.g., which object, how the bone is referenced) and doesn't mention that it modifies an existing group.
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 provided on when to use this tool versus alternatives like set_vertices or create_vertex_group. There is no mention of prerequisites (e.g., the vertex group must exist) or conditions under which this tool should be chosen.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.