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effect_auto_duck

Automatically reduce volume of a track when audio is detected on a control track, such as lowering music during narration.

Instructions

Auto Duck: automatically reduce volume when audio is detected on another track. Place the control track (e.g. narration) above the track to duck (e.g. music). Select the track to duck before running.

Args: duck_amount_db: How much to reduce volume in dB (-24 to 0). Default: -12 inner_fade_down_len: Inner fade down length in seconds (>= 0). Default: 0 inner_fade_up_len: Inner fade up length in seconds (>= 0). Default: 0 outer_fade_down_len: Outer fade down length in seconds (>= 0). Default: 0.5 outer_fade_up_len: Outer fade up length in seconds (>= 0). Default: 0.5 threshold_db: Threshold for duck trigger in dB (-100 to 0). Default: -30 maximum_pause: Maximum pause between ducking regions in seconds (>= 0). Default: 1.0

Input Schema

TableJSON Schema
NameRequiredDescriptionDefault
threshold_dbNo
maximum_pauseNo
duck_amount_dbNo
inner_fade_up_lenNo
outer_fade_up_lenNo
inner_fade_down_lenNo
outer_fade_down_lenNo
Behavior3/5

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

No annotations provided, so description carries full burden. It explains the effect behavior (reduce volume based on threshold, fades) but does not disclose whether the effect is destructive or reversible.

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?

Well-structured with a brief header, setup instructions, and a bulleted parameter list. The first sentence is slightly redundant with the name, but overall efficient.

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?

All parameters are explained, prerequisites are given, and no output schema is needed. However, it does not mention what the tool returns (e.g., success indication) or if the effect is applied instantly.

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 coverage is 0%, so description must explain parameters. It does so thoroughly: each parameter has a description with units (dB, seconds) and valid ranges (e.g., -24 to 0, >= 0), adding significant value beyond the bare schema titles.

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 'Auto Duck: automatically reduce volume when audio is detected on another track.' This is a specific verb+resource and distinguishes it from sibling tools like effect_amplify or effect_fade_in/out.

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?

Explicit instructions: 'Place the control track above the track to duck. Select the track to duck before running.' This gives clear context for when to use, though it does not explicitly list when not to use.

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

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