Insert a keyframe on an object property at a specific frame, with optional channel selection via index (0=X, 1=Y, 2=Z, or -1 for all).
Insert a keyframe on an object property at a specific frame. Use index for individual channels (0=X, 1=Y, 2=Z), or -1 for all channels.
| Name | Required | Description | Default |
|---|---|---|---|
| frame | Yes | ||
| index | No | ||
| value | No | ||
| object | Yes | ||
| data_path | 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 full responsibility for behavioral disclosure. It does not mention side effects such as overwriting existing keyframes, requirements for the object to be animatable, error conditions, or what happens if value is null. It only states the basic action and index semantics, which 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 two sentences with no filler. The core purpose is front-loaded, and the index explanation is efficient. Every word contributes meaning.
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?
Despite having an output schema, the description is incomplete for a complex animation tool. It omits crucial information about data_path syntax, value types, frame handling, and any limitations or prerequisites. The tool is not fully usable based on the description alone.
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 for all parameters. It only explains the index parameter (0=X, 1=Y, 2=Z, -1 for all). It does not explain object, data_path, value, or frame formats/units. This is a significant gap for a tool with 5 parameters.
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 verb (insert) and resource (keyframe on an object property at a specific frame), which distinguishes it from many sibling tools. However, it does not explicitly differentiate from set_keyframes, which is a closely related sibling, so it lacks explicit sibling differentiation.
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?
The description provides parameter usage for the index field but gives no guidance on when to use this tool versus alternatives like set_keyframes or delete_keyframe. There is no mention of conditions that would make this tool the right choice, nor exclusions.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.