ffmpeg-render-pro

Overview Schema Source Related Servers Discussions Admin

Concatenate Videos

concat_videos

Destructive

Joins multiple video files into a single output using stream copy without re-encoding, validating codec/resolution/framerate/pixel format consistency by default.

Instructions

Join multiple video files into one with stream copy: no re-encoding, completes in seconds regardless of file size. All inputs must share the same codec, resolution, framerate, and pixel format. By default each input is probed with ffprobe and mismatches are rejected before ffmpeg runs, because ffmpeg itself accepts mismatched inputs and writes a silently corrupt file; set validate false to skip the probes for inputs known to be uniform. Prerequisite: ffmpeg installed. Side effect: overwrites output_path if it already exists.

Input Schema

TableJSON Schema

Name	Required	Description
`validate`	No	Probe every input with ffprobe and reject codec/resolution/framerate/pixel-format mismatches before concatenating. Default true. Skipped with a warning when ffprobe is not installed.
`input_files`	Yes	Video file paths to concatenate, in playback order. All must exist.
`output_path`	Yes	Output file path. Overwritten if it already exists.

Output Schema

TableJSON Schema

Name	Required	Description
`segments`	Yes	Absolute paths of the concatenated inputs, in order
`validated`	Yes	True when segment compatibility validation was requested
`outputPath`	Yes	Absolute output file path

Schema Changelog

Changes observed during successful MCP inspections.

Addedv1.5.2Sep 7, 2026

TDQS

A4.6/5.0

Behavior5/5

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

The description explicitly discloses the destructive side effect of overwriting output_path, aligning with the destructiveHint annotation. It also explains the validation behavior with ffprobe, the rejection of mismatched inputs, and the skip behavior when validate is false, giving a clear picture of execution behavior.

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

Conciseness4/5

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

The description is slightly long but well-structured with clear sections for purpose, constraints, validation, prerequisite, and side effect. The explanatory clause about why validation is needed is verbose but adds important rationale for the default behavior.

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

Completeness5/5

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

The description provides all necessary operational context: the lossless nature of the operation, input constraints, validation defaults, prerequisite software, and destructive side effects. This is sufficient for an agent to correctly invoke the tool without needing external documentation.

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

Parameters4/5

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

The schema already covers parameter descriptions at 100%, but the tool description adds meaningful context: it explains the impact of the validate flag, restates that input files must be in playback order, and confirms that output_path is overwritten. This goes beyond the schema without being redundant.

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 clearly states the tool's purpose: joining multiple video files into one using stream copy with no re-encoding. It immediately distinguishes this from a rendering or transcoding operation, making the tool's role unambiguous.

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

Usage Guidelines4/5

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

It explains when to use the tool (concatenation with matching codecs/parameters) and when to set validate to false for known-uniform inputs. It does not explicitly compare against sibling tools like render_video, but the 'no re-encoding' phrasing strongly implies the appropriate use case.

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

Deploy Server