Skip to main content
Glama
ronak-create

FableCut

by ronak-create
OverviewSchemaSourceRelated ServersDiscussionsAdmin
JavaScript
Hybrid

fablecut_scopes

Measure the graded picture at one moment — what the editor's scopes show, as numbers: luma levels (min, 1st percentile, median, mean, 99th percentile, max on 0–1), the % of pixels crushed to black / clipped to white, mean R/G/B, average…

Instructions

Measure the graded picture at one moment — what the editor's scopes show, as numbers: luma levels (min, 1st percentile, median, mean, 99th percentile, max on 0–1), the % of pixels crushed to black / clipped to white, mean R/G/B, average saturation, and the colour cast of the midtones (hue name + strength; neutral below 0.01), plus the clips on screen with their grades, masks, track mattes and blend modes. Rendered by the same compositor as export (an open editor tab, else headless Chrome / Edge), over the export frame when one is set. Use it to check a grade: e.g. a cast strength above ~0.03 on footage that should be neutral, whitePct above ~1 (clipped highlights), or a median far from ~0.4 for a normally exposed shot. The user's playhead does not move.

Input Schema

NameRequiredDescriptionDefault
maskNoAlso measure a clip's masks: {clip}. Adds how much of that clip's picture the masks keep (coverage %, the feathered matte measured alone) and how much of the frame the masked clip covers
timeNoTimeline seconds to measure (default: the editor's playhead)
matteNoAlso measure what one grade layer selects: {clip, layer} (layer = index into the clip's grade.layers). Adds the matte's coverage (% of that clip's picture) and the levels / colour of the selected pixels after grading
whereNoauto (default): an open editor tab, else headless · tab · headless
timeoutNoSeconds to wait (default 60)

Schema Changelog

Changes observed during successful MCP inspections.

  1. Changed1 schema field changedv1.14.0
    • addedInput schema / properties / mask
      Added value: +{
+  "description": "Also measure a clip's masks: {clip}. Adds how much of that clip's picture the masks keep (coverage %, the feathered matte measured alone) and how much of the frame the masked clip covers",
+  "properties": {
+    "clip": {
+      "type": "string"
+    }
+  },
+  "required": [
+    "clip"
+  ],
+  "type": "object"
+}
  2. Addedv1.11.0

TDQS

A4.2/5.0
Behavior4/5

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

With no annotations, the description carries the full burden and does well: it discloses the rendering path (same compositor as export; open editor tab else headless Chrome/Edge), that measurement is over the export frame when set, the non-mutating nature (playhead does not move), and a sensible default timeout. It omits failure modes and any statement of required permissions, keeping it short of a 5.

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?

Purpose is front-loaded, but the middle sentence is a dense enumeration of every returned metric, and the numeric examples with tilde thresholds add length. Because there is no output schema, spelling out the returns earns its place, so the density is justified rather than wasteful.

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?

Complex, nested-object tool with no output schema, yet the description fully enumerates the return values and semantics (levels, clipped/crushed percentages, cast hue/strength with a neutral cutoff), the rendering fallback, and the default frame/time behavior. An agent has everything it needs to call it and interpret results.

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?

Schema description coverage is 100%, so the schema already documents all five parameters including the nested mask/matte objects and the where enum. The description adds only indirect semantics ('over the export frame when one is set', playhead default for time), so the baseline 3 is appropriate.

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?

States a specific verb and resource ('Measure the graded picture at one moment') plus exactly what the tool returns (numeric luma levels, clip/clip percentages, RGB means, saturation, colour cast, on-screen clips with grades/mattes/blends). Calling out that it returns numbers and is rendered by the same compositor as export implicitly separates it from image-producing siblings like fablecut_frame and fablecut_export.

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?

Gives concrete when-to-use guidance with actionable thresholds ('cast strength above ~0.03 on footage that should be neutral', 'whitePct above ~1', 'median far from ~0.4'). It clarifies that the playhead is not moved, but never names an alternative sibling or states when not to use it, so the guidance is strong but not fully routing.

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