Retrieves the frame numbers where a layer has keyframes, optionally filtered by start and end frames. Use it to inspect animation timing or locate keyframes for editing.
Frames at which a layer has keyframes.
| Name | Required | Description | Default |
|---|---|---|---|
| end | No | ||
| layer | No | ||
| start | No |
Changes observed during successful MCP inspections.
v0.3.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
No annotations are supplied, so the description carries the full burden and discloses almost nothing. It does not say whether the result is sorted, whether it covers the whole timeline when start/end are null, whether omitting the layer returns all layers, or what happens for a layer with no keyframes.
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?
It is a single short, front-loaded phrase with no wasted words, but the brevity reflects under-specification rather than discipline. Structurally it is not even a complete sentence, and no key information is prioritized because none is provided.
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 read-only listing tool with three optional parameters and no output schema, an agent mainly needs to know the scope semantics of the nullable parameters. The description leaves those unspecified, which is a real gap, though the low complexity of the operation keeps the omission from being severe.
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%, and all three parameters (layer, start, end) are optional with null defaults. The description only hints at the 'layer' parameter and adds nothing about the meaning or default behavior of start and end, so it fails to compensate for the schema gap.
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 text is a noun fragment ('Frames at which a layer has keyframes') that essentially restates the tool name list_keyframes. It never states a verb such as 'list' or 'return', and it does not distinguish the tool from siblings like 'keyframe' or 'animation_info', which plausibly overlap in the same animation domain.
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?
There is no when-to-use or when-not-to-use guidance, and no mention of alternatives such as animation_info (for general timeline data) or keyframe (for setting keyframes). The only guidance is an implied 'use this to see keyframes on a layer', which an agent could infer 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.