Skip to main content
Glama
CarlxsMG

UEAgent

by CarlxsMG
OverviewSchemaSourceRelated ServersDiscussionsAdmin
Local

set_section_pre_post_rollout

DestructiveIdempotent

Set pre-roll and post-roll frames on a sequencer section to control evaluation before and after its visible range. Pass 0 to clear either roll window.

Instructions

Set pre-roll and/or post-roll frames on a sequencer section. Pre-roll = frames the section evaluates BEFORE its visible range. Post-roll = frames the section evaluates AFTER its visible range. Both are stored as FFrameNumber on UMovieSceneSection. Pass at least one of pre_roll_frames or post_roll_frames (a non-None value). A 0 value means "no roll" (clears the roll window). The values are written via the inline SetPreRollFrames / SetPostRollFrames setters and read back through the section's public FFrameNumber fields.

Returns: { sequence_path: string, pre_roll_frames: int, post_roll_frames: int, set: bool, saved: bool, save_error?: string }

Input Schema

TableJSON Schema
NameRequiredDescriptionDefault
track_typeNoOptional class filter ("transform"|"audio"|"event"|"fade"|etc.). Default "transform".
track_indexNoIndex into the binding's tracks (0 = first track, default 0; used when track_type is omitted).
binding_guidNoGUID string of the binding the section lives under.
section_indexNoIndex of the section on the resolved track (default 0).
sequence_nameNoAlias for sequence_path.
sequence_pathNoAsset path of the Level Sequence.
pre_roll_framesNoOptional pre-roll frames (omit to leave unchanged).
post_roll_framesNoOptional post-roll frames (omit to leave unchanged).
binding_name_or_guidNoAlias for binding_guid, read only when binding_guid is absent; it must also be a GUID string, a bound object's name is not resolved.

Schema Changelog

Changes observed during successful MCP inspections.

  1. Changed2 schema fields changedv1.2.0
    • changedInput schema / properties / binding_name_or_guid / description
      Previous value: -"Sequencer binding: the bound object's name or its GUID string"New value: +"Alias for binding_guid, read only when binding_guid is absent; it must also be a GUID string, a bound object's name is not resolved."
    • removedInput schema / required
      Removed value: -[
-  "sequence_path",
-  "binding_guid"
-]
  2. First observedv1.1.0

TDQS

A3.8/5.0
Behavior4/5

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

Annotations already declare destructiveHint=true, idempotentHint=true and readOnlyHint=false, lowering the bar. On top of that the description discloses that both values are stored as FFrameNumber on UMovieSceneSection, that a 0 clears the roll window, and that values are written via inline setters and read back through public fields – useful persistence semantics beyond the annotations.

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?

Front-loaded with the core action, then definitions and constraints in tight sentences. The embedded 'Returns: {...}' block is mildly verbose but justifies itself given no output schema exists.

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

Completeness4/5

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

For a 9-param (0 required) mutation with no output schema, the description covers the essential semantics and even spells out the return shape. It leaves track/binding/sequence resolution details to the schema, which is reasonable but not exhaustive, so it falls just short of fully self-sufficient.

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 description coverage is 100%, so the baseline is 3. The description adds genuine meaning: pre-roll/post-roll are the frames evaluated before/after the visible range, omitting a value leaves it unchanged, and 0 means 'no roll'. This clarifies the two key parameters beyond the schema text.

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?

States a specific verb (Set) and resource (pre-roll/post-roll frames on a sequencer section) and clearly scopes what each roll type means. It does not name or contrast with any sibling tool (e.g. set_section_range, set_section_active), so it is clear but not sibling-differentiated.

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?

Provides a hard usage constraint ('Pass at least one of pre_roll_frames or post_roll_frames') and explains the 0-value semantics, which implies correct usage. However, it gives no when-to-use vs. when-not guidance and never mentions alternatives among the many set_section_* siblings.

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