Set a keyframe on a Houdini parameter at a specified frame with value, tangent slope, and acceleration.
Set a single keyframe on a parameter.
Args: node_path: Node path. parm_name: Parameter name. frame: Frame number. value: Value at this keyframe. slope: Tangent slope. accel: Acceleration.
| Name | Required | Description | Default |
|---|---|---|---|
| accel | No | ||
| frame | Yes | ||
| slope | No | ||
| value | Yes | ||
| node_path | Yes | ||
| parm_name | Yes |
Changes observed during successful MCP inspections.
v0.1.0Does 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 states 'set', implying a mutation, but does not reveal whether this overwrites an existing keyframe, how it interacts with existing animation, or what the tool returns. This is a significant gap for an operation that modifies scene data.
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 brief, which is positive, but the structure is a simple list of parameter names without elaboration. It is concise but under-specified; the arg list is not informative enough to help the agent understand the tool's behavior.
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 6-parameter tool with no annotations and no output schema, this description is severely lacking. It fails to explain the meaning of slope and accel, potential side effects (like overwriting), prerequisites, or return values. An agent cannot reliably invoke this tool based on the provided information.
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 by explaining each parameter. It lists names like 'slope' and 'accel' without defining their meaning, units, or acceptable ranges. The bare list adds no value beyond the schema's property names, leaving the agent to guess semantics.
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 and resource: 'Set a single keyframe on a parameter.' The word 'single' distinguishes it from sibling set_keyframes (plural), so an agent can differentiate the tools without extra context.
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 set_keyframes (plural) or delete_keyframe. There is no mention of prerequisites, such as whether the node must already exist or the parameter must be animatable, and no alternative is named.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.