Set up an inverse kinematics chain on an armature by specifying chain bones and an optional pole target to control rigging.
Set up an IK (Inverse Kinematics) chain.
Args: armature_name: Target armature. chain_bones: List of bone names in the chain. pole_target: Pole target object name.
| Name | Required | Description | Default |
|---|---|---|---|
| chain_bones | Yes | ||
| pole_target | No | ||
| armature_name | Yes |
Changes observed during successful MCP inspections.
v3.0.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
There are no annotations, so the description carries the full burden of explaining behavior. It mentions that an IK chain is set up and lists arguments, but it does not disclose side effects, prerequisites, required modes, or what happens to the existing armature or constraints.
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 and well-structured: a one-sentence purpose followed by a clean argument list. Every line adds necessary information, and the wording is free of extraneous detail.
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 mutating tool with no annotations and no output schema, the description leaves important gaps. It does not explain prerequisites like an existing armature and bones, the role of the optional pole target, or what the expected result is. An agent can infer the basic call but not fully reason about consequences and failure conditions.
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 0% description coverage, so the parameter descriptions in the tool text provide essential meaning. However, they are minimal: "Target armature" and "Pole target object name" add only slightly more than the schema titles, while "List of bone names in the chain" clarifies chain_bones. This is adequate but not thorough.
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 states a specific action and resource: "Set up an IK (Inverse Kinematics) chain." It clearly identifies the tool's purpose, but it does not differentiate it from sibling tools like add_bone_constraint or create_humanoid_rig, so it falls short of full sibling distinction.
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, nor are prerequisites or exclusion conditions mentioned. The description only states what the tool does, leaving the agent to infer appropriate usage from the name alone.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.