Trim a video clip by specifying start and end times or duration, then save the result to a new output file.
Trim a clip to start/end or start+duration and write output_path.
| Name | Required | Description | Default |
|---|---|---|---|
| end | No | ||
| start | No | ||
| duration | No | ||
| overwrite | No | ||
| input_path | Yes | ||
| output_path | Yes | ||
| stream_copy | No | ||
| allow_any_path | No |
| Name | Required | Description | Default |
|---|---|---|---|
No arguments | |||
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 behavioral burden. It discloses that an output path is written, but omits significant behavior: overwrite defaults to true and may replace an existing file, stream_copy controls re-encoding, allow_any_path restricts allowed paths, and no mention is made of ffmpeg dependency or return behavior.
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?
A single sentence with no filler, front-loaded with the core action. It is compact and scannable, though a structured mention of the trim modes could improve clarity further.
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?
With 8 parameters, 0% schema coverage, and no annotations, the description is too thin to fully support invocation. Critical constraints—mutual exclusivity of end vs duration, default overwrite behavior, path safety flag, and time units—are missing even though an output schema exists.
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. It clarifies the relationship between start, end, and duration and names output_path, but leaves the other five parameters (overwrite, stream_copy, allow_any_path) and the units/format of timestamps unexplained.
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 identifies a specific verb and resource ('trim a clip') and states the two trim modes (start/end or start+duration) plus an output destination. It is clearly distinct from siblings like concat_clips, though it does not explicitly compare itself to other tools such as run_ffmpeg.
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 choose this tool over alternatives like run_ffmpeg, concat_clips, or verify_edit. The phrase 'Trim a clip' only implies intent; there are no prerequisites, exclusions, or selection conditions.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.