Skip to main content
Glama
Sign In
mcp-ffmpeg

mcp-ffmpeg

by kevinten-ai
OverviewSchemaSourceRelated ServersDiscussionsAdmin
Python
Local

add_image_overlay

Add an image (watermark or logo) onto a video at a specified position, with control over opacity, timing, and size. Solves the need to brand or annotate video content.

Instructions

Adds an image overlay (watermark/logo) to a video.

Args: video_path: Path to the input video file. output_video_path: Path to save the video with the image overlay. image_path: Path to the image file for the overlay. position: Position of the overlay. Options: 'top_left', 'top_right', 'bottom_left', 'bottom_right', 'center'. Or specify custom coordinates like 'x=10:y=10'. opacity: Opacity of the overlay (0.0 to 1.0). If None, image's own alpha is used. start_time: Start time for the overlay (HH:MM:SS or seconds). If None, starts from beginning. end_time: End time for the overlay (HH:MM:SS or seconds). If None, lasts till end. width: Width for the overlay image (e.g., '100', 'iw0.1'). Original if None. height: Height for the overlay image (e.g., '50', 'ih0.1'). Original if None. Returns: A status message indicating success or failure.

Tool call template

Replace each placeholder with a value matching the input schema. Only required parameters are included; add optional parameters as needed.

{
  "id": 1,
  "jsonrpc": "2.0",
  "method": "tools/call",
  "params": {
    "arguments": {
      "video_path": "<video_path>",
      "output_video_path": "<output_video_path>",
      "image_path": "<image_path>"
    },
    "name": "add_image_overlay"
  }
}

Input Schema

NameRequiredDescriptionDefault
widthNo
heightNo
opacityNo
end_timeNo
positionNotop_right
image_pathYes
start_timeNo
video_pathYes
output_video_pathYes

Output Schema

NameRequiredDescriptionDefault
resultYes

Schema Changelog

Changes observed during successful MCP inspections.

  1. First observedv1.0.0

TDQS

A4.3/5.0
Behavior4/5

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

With no annotations, the description carries the full burden. It adds meaningful behavioral context: default handling for opacity (uses image's alpha if None), start/end time behavior (full length if None), and position format options. However, it does not mention potential side effects like file overwriting or format constraints, but the return type and parameter defaults are well disclosed.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Conciseness5/5

Is the description appropriately sized, front-loaded, and free of redundancy?

The description is well-structured: a front-loaded one-sentence summary, then a clean Args section with each parameter on its own line, followed by a Returns note. Every line adds necessary information without redundancy; the length is justified by the number of parameters.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Completeness4/5

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

Given the tool's moderate complexity (9 params, no annotations, minimal schema), the description is fairly complete. It covers all parameter behaviors and returns a status message, and an output schema exists for return details. Minor gaps include lack of explicit format support or overwrite behavior, but these are not critical for typical usage.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Parameters5/5

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema description coverage is 0%, so the description fully compensates. It explains each parameter in detail: position options including custom coordinate syntax, opacity range and default behavior, time formats, and width/height expression examples (e.g., 'iw*0.1'). This goes far beyond the basic types and defaults in the schema.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Purpose5/5

Does the description clearly state what the tool does and how it differs from similar tools?

The description starts with a clear, specific verb phrase: 'Adds an image overlay (watermark/logo) to a video.' This identifies the action, the target resource (video), and the object (image overlay), distinguishing it from siblings like add_text_overlay and add_subtitles.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Usage Guidelines3/5

Does the description explain when to use this tool, when not to, or what alternatives exist?

The description implies usage—use this when you need to overlay an image—but it does not explicitly compare with alternatives or state when not to use it. No exclusions or sibling references are provided, so the guidance is inferred rather than direct.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.

Deploy Server

Other Tools