Add IK, copy rotation, copy location, or limit rotation constraints to a pose bone to control its animation behavior.
Add a constraint to a pose bone. Types: IK, COPY_ROTATION, COPY_LOCATION, LIMIT_ROTATION.
| Name | Required | Description | Default |
|---|---|---|---|
| bone | Yes | ||
| name | No | ||
| type | Yes | ||
| object | 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, the description carries the full burden. It only says 'Add a constraint', implying mutation, but doesn't disclose side effects, required object/bone existence, default constraint settings, error behavior, or return value. This is insufficient for a mutation 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 a single, efficient sentence that front-loads the action and lists supported types. It's appropriately concise for the limited information it conveys, though it could afford more detail without becoming verbose.
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 mutation tool with no annotations and an output schema (unseen), the description is incomplete. It lacks essential context about prerequisites, parameter semantics, and behavioral outcomes, making it difficult for an agent to invoke correctly without additional knowledge.
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 only clarifies the 'type' parameter by listing valid values. The 'object' (presumably armature), 'bone' (bone name), and 'name' (constraint name) are left undefined, leaving the agent to guess their meaning.
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 ('Add a constraint') and the target ('pose bone'), and lists specific constraint types (IK, COPY_ROTATION, etc.), which distinguishes it from generic add_constraint. However, it doesn't explicitly contrast with sibling tools like add_constraint, so it's not fully 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 on when to use this tool versus alternatives like add_constraint or set_constraint_property. It doesn't mention prerequisites (e.g., the object must be an armature) or conditions that would make this tool preferable.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.