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Glama

tail

DestructiveIdempotent

Read or change the finishing pass shown after a project's last frame: set an end card or bumper, its full length, fade, reset, or preview with plan. Export applies it so the pass is not dropped.

Instructions

Read or change the finishing pass this project plays after its last frame.

An end card or a bumper, applied by export itself rather than glued on afterward with ffmpeg — the fix for a defect that has already shipped: a finishing pass applied downstream of export is dropped by every derivation at exit 0, silently, because nothing in the project ever knew it existed (HISTORY.md § The bumper the teaser never had, § The end card). Call it with no arguments to read what is in force.

asset must be card:name, never a clip_id — verify diffs a render's own transcription against the timeline's words, and silence adds none of its own, which is exactly what a card behind it guarantees and a media clip would not. seconds is the tail's whole length, card included, not a hold with fade added on top of it (the known trap: xfade finishes exactly at the length it is given). fade dissolves the card in over the film's last frames; 0 cuts to it hard. A music bed's over_tail keeps the music playing under the card.

Setting asset or seconds for the first time needs both together; either alone after that updates just that field, the same partial-update shape caption_style has. reset drops the tail entirely.

The card follows the cues' picture lane, or with none the timeline's own track, so a screen recording takes a tail as it is. A sound-only film with no cues is refused by export, by name. plan resolves and validates without writing.

Input Schema

TableJSON Schema
NameRequiredDescriptionDefault
fadeNoSeconds the card dissolves in over the film's last frames, opaque on the tail's first frame — overlapping the film, never added to `seconds`. 0 cuts to the card hard.
pathNoThe project directory to act on. Omit it — the usual case — when this server is bound to a project (started as `proofcut -C DIR mcp`, or inside a project; `ping` says which): it then resolves to that one bound project, a relative path resolves against it, and a path outside it is refused by name. Unbound, `path` is the whole address and omitting it refuses rather than guessing.
planNoResolve the whole call and report what it would do, writing nothing. Prefer it over doing the thing and undoing it.
assetNoThe end card or bumper, as `card:name` — never a clip id. `verify` diffs the render's own transcription against the timeline's words, and a card behind silence adds none of its own, which a media clip would.
resetNoDrop the tail entirely. Note a derivation inherits none of it anyway and reports `tail_dropped`.
secondsNoThe tail's **whole** length, card included — not a hold with `fade` added on top of it.

Output Schema

TableJSON Schema
NameRequiredDescriptionDefault

No arguments

Schema Changelog

Changes observed during successful MCP inspections.

  1. Changed1 schema field changedv0.37.0
    • changedInput schema / properties / fade / description
      Previous value: -"Recorded and echoed, not yet drawn: this build cuts to the card hard, at `seconds`."New value: +"Seconds the card dissolves in over the film's last frames, opaque on the tail's first frame — overlapping the film, never added to `seconds`. 0 cuts to the card hard."
  2. Changed21 schema fields changedv0.25.0
    • removedInput schema / properties / asset / anyOf
      Removed value: -[
      -  {
      -    "type": "string"
      -  },
      -  {
      -    "type": "null"
      -  }
      -]
    • addedInput schema / properties / asset / description
      Added value: +"The end card or bumper, as `card:name` — never a clip id. `verify` diffs the render's own transcription against the timeline's words, and a card behind silence adds none of its own, which a media clip would."
    • removedInput schema / properties / asset / title
      Removed value: -"Asset"
    • addedInput schema / properties / asset / type
      Added value: +[
      +  "string",
      +  "null"
      +]
    • removedInput schema / properties / fade / anyOf
      Removed value: -[
      -  {
      -    "type": "number"
      -  },
      -  {
      -    "type": "null"
      -  }
      -]
    • addedInput schema / properties / fade / description
      Added value: +"Recorded and echoed, not yet drawn: this build cuts to the card hard, at `seconds`."
    • removedInput schema / properties / fade / title
      Removed value: -"Fade"
    • addedInput schema / properties / fade / type
      Added value: +[
      +  "number",
      +  "null"
      +]
    • removedInput schema / properties / path / anyOf
      Removed value: -[
      -  {
      -    "type": "string"
      -  },
      -  {
      -    "type": "null"
      -  }
      -]
    • addedInput schema / properties / path / description
      Added value: +"The project directory to act on. Omit it — the usual case — when this server is bound to a project (started as `proofcut -C DIR mcp`, or inside a project; `ping` says which): it then resolves to that one bound project, a relative path resolves against it, and a path outside it is refused by name. Unbound, `path` is the whole address and omitting it refuses rather than guessing."
    • removedInput schema / properties / path / title
      Removed value: -"Path"
    • addedInput schema / properties / path / type
      Added value: +[
      +  "string",
      +  "null"
      +]
    • addedInput schema / properties / plan / description
      Added value: +"Resolve the whole call and report what it would do, writing nothing. Prefer it over doing the thing and undoing it."
    • removedInput schema / properties / plan / title
      Removed value: -"Plan"
    • addedInput schema / properties / reset / description
      Added value: +"Drop the tail entirely. Note a derivation inherits none of it anyway and reports `tail_dropped`."
    • removedInput schema / properties / reset / title
      Removed value: -"Reset"
    • removedInput schema / properties / seconds / anyOf
      Removed value: -[
      -  {
      -    "type": "number"
      -  },
      -  {
      -    "type": "null"
      -  }
      -]
    • addedInput schema / properties / seconds / description
      Added value: +"The tail's **whole** length, card included — not a hold with `fade` added on top of it."
    • removedInput schema / properties / seconds / title
      Removed value: -"Seconds"
    • addedInput schema / properties / seconds / type
      Added value: +[
      +  "number",
      +  "null"
      +]
    • removedInput schema / title
      Removed value: -"tailArguments"
  3. First observedv0.24.0

TDQS

A4.6/5.0
Behavior5/5

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

Beyond annotations, the description explains the mutation semantics in detail: `reset` drops the tail, setting `asset`/`seconds` first requires both, later updates are partial, `plan` writes nothing, and downstream application drops tails silently. It also discloses edge-case behavior such as sound-only films being refused by `export`. No contradiction with 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?

The description is long but well-organized into themed paragraphs: purpose, parameter pitfalls, update behavior, and edge cases. Each sentence adds substantive detail, though some historical references (HISTORY.md sections) are tangential. Front-loading is strong.

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 mutation tool with 6 parameters, an output schema, and annotations, the description covers all essential behavior: reading, updating, resetting, planning, path semantics are delegated to schema, and niche cases like cue lanes and sound-only films are addressed. Nothing critical is missing.

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?

Input schema already has 100% coverage, so the baseline is 3. The description adds meaningful cross-parameter semantics not present in the schema: the first-time set requires both `asset` and `seconds`, the `seconds` vs `fade` known trap, and the `over_tail` music-bed interaction.

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?

Opens with a specific verb and resource: 'Read or change the finishing pass this project plays after its last frame.' It clearly distinguishes the tail as an end card/bumper applied by `export`, not a downstream ffmpeg overlay, separating it from sibling tools like finish_report or export itself.

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 clear context for when to use the tool: to fix a shipped defect, to read the current tail with no arguments, or to use `plan` for a dry run. It contrasts with the ffmpeg-glue-on approach and references the `caption_style` partial-update shape. However, it does not explicitly name alternative tools or state hard when-not-to-use conditions.

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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