Build a basic humanoid armature with spine, arms, and legs at any location. Use it to set up a character skeleton for animation and posing.
Create a basic humanoid armature with spine, arms, and legs.
Args: armature_name: Name for the armature. location: [x, y, z] position.
| Name | Required | Description | Default |
|---|---|---|---|
| location | No | ||
| armature_name | No | HumanRig |
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. It only says 'Create a basic humanoid armature' but does not explain side effects (e.g., whether it replaces existing armatures), whether the new armature becomes active, or any prerequisites. This is a significant gap for a creation tool.
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 efficient: a single purpose sentence and a concise args list. The purpose is front-loaded and the parameter explanations are minimal but sufficient. No wasted words.
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 2-parameter tool with no output schema and no annotations, the description covers purpose and parameters but lacks usage context, behavioral details, and any distinction from the very similar create_armature sibling. An agent would not know when to choose this tool or what happens after creation, making it incomplete for confident invocation.
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 explain parameters. It does: armature_name is the name, location is an [x, y, z] position. This adds meaning beyond the schema's bare titles and defaults. It could add context like coordinate system, but the core meaning is clear.
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 it creates a basic humanoid armature with spine, arms, and legs. This is a specific verb and resource that distinguishes it from generic siblings like create_armature and add_bone. The mention of specific anatomical parts makes the purpose unambiguous.
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 use this tool versus alternatives such as create_armature or setup_ik_chain. The description only states what it does, not the conditions that would make it the preferred choice. There is no mention of exclusions or alternative tools.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.