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Glama

fablecut_proxy

Proxies: light H.264 copies (540p by default, 720p or 1080p; never larger than the source) of heavy footage — 4K, HEVC, ProRes, long phone clips — that the editor plays while the user edits, so playback and scrubbing stay smooth.

Instructions

Proxies: light H.264 copies (540p by default, 720p or 1080p; never larger than the source) of heavy footage — 4K, HEVC, ProRes, long phone clips — that the editor plays while the user edits, so playback and scrubbing stay smooth. Export, fablecut_frame, fablecut_scopes and every measurement always read the original, so a proxy never changes the result. Without create or delete it reports each video's proxy (ready, being made with its progress, failed, none). create:true makes them (one at a time, in the background on the server) and waits until they are done unless wait:false; delete:true removes them. mediaIds defaults to every video in the project. The user turns proxy playback on or off with the monitor's Proxy button. Needs ffmpeg on PATH.

Input Schema

NameRequiredDescriptionDefault
waitNoWith create: wait until every proxy is done (default true)
createNoMake proxies for these files
deleteNoDelete their proxies
heightNoProxy height in pixels (default 540)
timeoutNoSeconds to wait with create (default 900)
mediaIdsNoVideo media ids (default: all video media)

Schema Changelog

Changes observed during successful MCP inspections.

  1. Addedv1.16.0

TDQS

A4.9/5.0
Behavior5/5

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

With no annotations provided, the description carries the full behavioral burden and does so well: it discloses background server-side creation, one-at-a-time processing, wait behavior, status reporting including progress and failure, deletion behavior, and the ffmpeg dependency. It also clearly states the critical invariant that proxies never affect export or measurement results.

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 front-loaded with what a proxy is and why it matters, then moves through reporting, creation, deletion, defaults, and prerequisites. Despite being dense, every sentence contributes operational context and there is no wasteful repetition.

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?

For a six-parameter tool with no output schema and no annotations, the description is complete enough to call correctly: it covers the default report mode, create/delete behavior, wait semantics, default media scope, playback implications, status values, and the ffmpeg requirement. No major agent decision is left without guidance.

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?

Schema coverage is 100%, so the baseline is 3, but the description adds meaningful semantics beyond the schema for create, delete, wait, height, and mediaIds. It explains defaults such as mediaIds covering every video in the project and height never exceeding the source, though timeout is left primarily to 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 states a specific verb and resource: it proxies heavy video footage with light H.264 copies for smooth editing playback, while also reporting, creating, or deleting proxies. It clearly distinguishes proxy behavior from export, frame extraction, and scopes by explaining that those always read the original.

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

Usage Guidelines5/5

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

It explicitly identifies the use case: heavy footage such as 4K, HEVC, ProRes, and long phone clips that need smooth playback and scrubbing. It also clarifies when create/delete are omitted versus set, and warns that export, fablecut_frame, fablecut_scopes, and every measurement read the original, which effectively routes the agent away from using proxies for final results.

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