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ffmpeg_raw

Run a restricted local FFmpeg command. Inputs and the final output must be workspace paths; network protocols, filters, and arbitrary FFmpeg options are not supported.

Instructions

Run a restricted local FFmpeg command. Inputs and the final output must be workspace paths; network protocols, filters, and arbitrary FFmpeg options are not supported.

Input Schema

NameRequiredDescriptionDefault
argsYesLimited FFmpeg arguments, for example ['-i', 'input.mp4', '-c:v', 'libx264', 'output.mp4']

Schema Changelog

Changes observed during successful MCP inspections.

  1. Changed1 schema field changedv1.0.3
    • changedInput schema / properties / args / description
      Previous value: -"Array of FFmpeg arguments (e.g., ['-i', 'input.mp4', '-vf', 'scale=1280:720', 'output.mp4'])"New value: +"Limited FFmpeg arguments, for example ['-i', 'input.mp4', '-c:v', 'libx264', 'output.mp4']"
  2. First observedv1.0.2

TDQS

A3.5/5.0
Behavior3/5

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

With no annotations, the description carries the full burden. It discloses key restrictions (local only, no network, no filters, workspace paths) but omits whether the command writes files, potential overwrites, error handling, or execution return details. This is useful but incomplete for a command-execution tool.

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?

Two sentences, front-loaded with purpose then restrictions. No wasted words, and the critical constraints are clearly separated.

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

Completeness3/5

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

For a one-parameter tool with no output schema or annotations, the description covers restrictions and workspace path requirements but doesn't explain return behavior, error modes, or whether execution is synchronous. It is adequate but leaves gaps an agent might need for correct invocation.

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

Parameters3/5

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

The single 'args' parameter has full schema coverage, including an example, so the schema itself provides adequate semantics. The description adds no further meaning about the parameter beyond reiterating input/output path constraints, which is baseline 3 given the high coverage.

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

Purpose4/5

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

The description clearly states the tool runs a restricted local FFmpeg command, specifying verb and resource. It doesn't explicitly differentiate from sibling tools like convert or cut_video, but the 'raw' nature and restrictions imply a lower-level, general-purpose alternative.

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 lists what is not supported (network protocols, filters, arbitrary options) and the workspace path requirement, which helps avoid misuse. However, it doesn't explicitly state when to use this tool instead of the more specific siblings, leaving the agent to infer that it's for custom FFmpeg operations not covered by them.

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