Overlay a logo image onto a video at a selected position to protect or brand your content. Provide the video and logo paths, then choose where the watermark appears.
Overlay a logo image (PNG with transparency works best) on top of a video.
| Name | Required | Description | Default |
|---|---|---|---|
| position | No | Where to place the logo. Default bottom-right. | |
| logo_path | Yes | Local path to the logo image | |
| video_path | Yes | Local path to the video |
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, but it only describes the action and offers a logo-format tip. It does not state whether the source video is modified in place, where output is written, or what side effects or dependencies exist.
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 sentence with no filler, and the core action is front-loaded. Every word contributes to understanding the tool's purpose.
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 media-mutation tool with no annotations and no output schema, the lack of output/file behavior is a significant gap. An agent knows what the tool does but not whether it overwrites the input video or what the tool returns.
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 100%, so the baseline is 3; the description adds only the 'PNG with transparency works best' tip for logo_path. Position semantics are already fully covered by the schema's enum and default.
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 states a specific verb and resource: 'Overlay a logo image ... on top of a video.' It also distinguishes from the sibling overlay_text by focusing on a logo image, though it never explicitly names alternatives.
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 provided on when to use this tool versus alternatives like overlay_text or burn_subtitles. Usage must be inferred entirely from the verb and resource, with no conditions, exclusions, or workflow context.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.