Premiere Pro MCP Server

Overwrite Clip

overwrite_clip

Overwrites a project item onto selected timeline tracks and verifies the new source placement at the requested time; reports unverified when streams cannot fit the chosen tracks.

Instructions

Overwrite a project item onto validated timeline tracks and verify a new source placement at the requested time. Every video/audio stream the item actually has must land on the requested tracks; a picture-only or sound-only placement (for example 5.1 audio that does not fit a stereo track) is committed_unverified, not verified. Video-only and audio-only items overwrite only the receiving track, so Sequence.overwriteClip cannot smash V0 or A0 for the unused kind.

Input Schema

Name	Required	Description
`item_id`	Yes	Node ID or name of the project item to add
`track_index`	No	Video track index (0-based, default: 0)
`start_seconds`	No	Start time in seconds on the timeline (default: 0)
`idempotency_key`	No	Optional client-chosen key (1-128 chars of A-Z a-z 0-9 . _ : -) for this intended edit. Pass a fresh key per edit and reuse it only when retrying that same edit, for example after a client-side timeout. A repeat with the same tool, key and arguments is not run again: while the first call is running it fails with IDEMPOTENCY_IN_PROGRESS (poll get_last_operations); after it finished it returns the original outcome marked replayed. A definite failure with nothing applied (receipt outcome not_applied) may be retried with the same key. Reusing a key with different arguments fails with IDEMPOTENCY_KEY_REUSED. Scoped to this MCP session (the stdio server process or one HTTP session) and held in memory only (200 keys, 1 hour); it does not survive a restart or reconnect. Read-only invocations are never deduplicated.
`audio_track_index`	No	Audio track index (0-based, default: 0), or "auto_empty" to use the lowest audio track with no clip in the placement range (for example when overwriting a nested sequence above existing music). auto_empty refuses, changing nothing, when every audio track is occupied there.
`expected_cep_target`	No	Optional reviewed CEP sequence/clip identity and exact tick ranges. Checked before every generated command; UXP refuses this CEP-only guard.
`expected_project_path`	No	Optional absolute saved-project path. Every generated CEP command refuses before its body when the active project differs or is unsaved. UXP commands refuse this CEP-only guard; local-only tools do not inspect Premiere. Omit to keep existing behavior.

Output Schema

Name	Required	Description
`ok`	Yes	Whether the tool completed successfully.
`data`	No	Tool-specific result data when ok is true; on failure, diagnostic detail when the tool provides it.
`tool`	Yes	The registered MCP tool name.
`error`	No	Failure detail when ok is false.
`receipt`	No	Versioned common mutation receipt; success never implies rendered verification.
`idempotency`	No	Present when idempotency_key deduplicated this call: replayed is true when the original outcome was returned instead of running again.

Schema Changelog

Changes observed during successful MCP inspections.

Changed2 schema fields changedv1.25.0Oct 24, 2026

addedInput schema / properties / idempotency_key

Added value: +{
+  "description": "Optional client-chosen key (1-128 chars of A-Z a-z 0-9 . _ : -) for this intended edit. Pass a fresh key per edit and reuse it only when retrying that same edit, for example after a client-side timeout. A repeat with the same tool, key and arguments is not run again: while the first call is running it fails with IDEMPOTENCY_IN_PROGRESS (poll get_last_operations); after it finished it returns the original outcome marked replayed. A definite failure with nothing applied (receipt outcome not_applied) may be retried with the same key. Reusing a key with different arguments fails with IDEMPOTENCY_KEY_REUSED. Scoped to this MCP session (the stdio server process or one HTTP session) and held in memory only (200 keys, 1 hour); it does not survive a restart or reconnect. Read-only invocations are never deduplicated.",
+  "maxLength": 128,
+  "minLength": 1,
+  "pattern": "^[A-Za-z0-9._:-]+$",
+  "type": "string"
+}

addedOutput schema / properties / idempotency

Added value: +{
+  "additionalProperties": true,
+  "description": "Present when idempotency_key deduplicated this call: replayed is true when the original outcome was returned instead of running again.",
+  "type": "object"
+}

Changed4 schema fields changedv1.24.3Oct 23, 2026

changedInput schema / properties / audio_track_index / description

Previous value: -"Audio track index (0-based, default: 0)"New value: +"Audio track index (0-based, default: 0), or \"auto_empty\" to use the lowest audio track with no clip in the placement range (for example when overwriting a nested sequence above existing music). auto_empty refuses, changing nothing, when every audio track is occupied there."

addedInput schema / properties / audio_track_index / minimum
```
Added value: +0
```
addedInput schema / properties / audio_track_index / pattern
```
Added value: +"^auto_empty$"
```

changedInput schema / properties / audio_track_index / type

Previous value: -"number"New value: +[
+  "integer",
+  "string"
+]

Changed3 schema fields changedv1.24.0Oct 12, 2026

addedInput schema / properties / expected_cep_target

Added value: +{
+  "additionalProperties": false,
+  "anyOf": [
+    {
+      "required": [
+        "sequence_id"
+      ]
+    },
+    {
+      "required": [
+        "source_item"
+      ]
+    }
+  ],
+  "description": "Optional reviewed CEP sequence/clip identity and exact tick ranges. Checked before every generated command; UXP refuses this CEP-only guard.",
+  "properties": {
+    "backend": {
+      "const": "cep",
+      "description": "Backend namespace for these IDs.",
+      "type": "string"
+    },
+    "clip": {
+      "additionalProperties": false,
+      "description": "Optional exact reviewed timeline clip.",
+      "properties": {
+        "effect": {
+          "additionalProperties": false,
+          "description": "Reviewed effect and parameter identity checked before mutation.",
+          "properties": {
+            "display_name": {
+              "description": "Optional exact host display name.",
+              "maxLength": 512,
+              "minLength": 1,
+              "type": "string"
+            },
+            "match_name": {
+              "description": "Effect match name from host inspection.",
+              "maxLength": 512,
+              "minLength": 1,
+              "type": "string"
+            },
+            "parameter_index": {
+              "description": "Inspected zero-based parameter index.",
+              "maximum": 255,
+              "minimum": 0,
+              "type": "integer"
+            },
+            "parameter_name": {
+              "description": "Exact inspected parameter name.",
+              "maxLength": 512,
+              "minLength": 1,
+              "type": "string"
+            }
+          },
+          "required": [
+            "match_name",
+            "parameter_index",
+            "parameter_name"
+          ],
+          "type": "object"
+        },
+        "end_ticks": {
+          "description": "Exact expected exclusive timeline end ticks.",
+          "pattern": "^-?\\d{1,30}$",
+          "type": "string"
+        },
+        "in_ticks": {
+          "description": "Exact expected source In ticks.",
+          "pattern": "^-?\\d{1,30}$",
+          "type": "string"
+        },
+        "node_id": {
+          "description": "Stable CEP node ID.",
+          "maxLength": 512,
+          "minLength": 1,
+          "type": "string"
+        },
+        "out_ticks": {
+          "description": "Exact expected exclusive source Out ticks.",
+          "pattern": "^-?\\d{1,30}$",
+          "type": "string"
+        },
+        "project_item_id": {
+          "description": "Expected source project-item node ID.",
+          "maxLength": 512,
+          "minLength": 1,
+          "type": "string"
+        },
+        "start_ticks": {
+          "description": "Exact expected timeline start ticks.",
+          "pattern": "^-?\\d{1,30}$",
+          "type": "string"
+        },
+        "track_index": {
+          "description": "Expected zero-based track index; identity still checked.",
+          "maximum": 255,
+          "minimum": 0,
+          "type": "integer"
+        },
+        "track_type": {
+          "description": "Expected media track group.",
+          "enum": [
+            "video",
+            "audio"
+          ],
+          "type": "string"
+        }
+      },
+      "required": [
+        "node_id",
+        "track_type",
+        "track_index"
+      ],
+      "type": "object"
+    },
+    "project_document_id": {
+      "description": "Exact Premiere project document ID observed during review.",
+      "maxLength": 512,
+      "minLength": 1,
+      "type": "string"
+    },
+    "sequence_id": {
+      "description": "Stable expected active sequence ID.",
+      "maxLength": 512,
+      "minLength": 1,
+      "type": "string"
+    },
+    "source_item": {
+      "additionalProperties": false,
+      "description": "Reviewed source identity for a source-only operation.",
+      "properties": {
+        "media_path": {
+          "description": "Optional exact source-media path.",
+          "maxLength": 4096,
+          "minLength": 1,
+          "type": "string"
+        },
+        "node_id": {
+          "description": "Exact project-item node ID.",
+          "maxLength": 512,
+          "minLength": 1,
+          "type": "string"
+        }
+      },
+      "required": [
+        "node_id"
+      ],
+      "type": "object"
+    }
+  },
+  "required": [
+    "backend"
+  ],
+  "type": "object"
+}

addedInput schema / properties / expected_project_path

Added value: +{
+  "description": "Optional absolute saved-project path. Every generated CEP command refuses before its body when the active project differs or is unsaved. UXP commands refuse this CEP-only guard; local-only tools do not inspect Premiere. Omit to keep existing behavior.",
+  "maxLength": 4096,
+  "minLength": 1,
+  "type": "string"
+}

addedOutput schema / properties / receipt

Added value: +{
+  "additionalProperties": true,
+  "description": "Versioned common mutation receipt; success never implies rendered verification.",
+  "type": "object"
+}

Changed2 schema fields changedv1.18.6Sep 30, 2026

addedInput schema / additionalProperties
```
Added value: +false
```

changedOutput schema / properties / data / description

Previous value: -"Tool-specific result data when ok is true."New value: +"Tool-specific result data when ok is true; on failure, diagnostic detail when the tool provides it."

Changed2 schema fields changedv1.14.4Aug 29, 2026

changedInput schema / $schema

Previous value: -"http://json-schema.org/draft-07/schema#"New value: +"https://json-schema.org/draft/2020-12/schema"

changedOutput schema / (root)

Previous value: -nullNew value: +{
+  "$schema": "https://json-schema.org/draft/2020-12/schema",
+  "additionalProperties": false,
+  "properties": {
+    "data": {
+      "description": "Tool-specific result data when ok is true."
+    },
+    "error": {
+      "description": "Failure detail when ok is false.",
+      "type": "string"
+    },
+    "ok": {
+      "description": "Whether the tool completed successfully.",
+      "type": "boolean"
+    },
+    "tool": {
+      "description": "The registered MCP tool name.",
+      "minLength": 1,
+      "type": "string"
+    }
+  },
+  "required": [
+    "ok",
+    "tool"
+  ],
+  "type": "object"
+}

Changed1 schema field changedv1.4.0Jul 27, 2026
- removedInput schema / additionalProperties
```
Removed value: -false
```
First observedv1.1.1May 28, 2026

TDQS

B3.4/5.0

Behavior4/5

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

Adds substantial non-annotated behavior: the outcome distinction between verified and committed_unverified, the rule that every stream must land on its requested track, and the documented Sequence.overwriteClip limitation for unused track kinds. It does not, however, state what existing clips in the placement range are replaced or removed, which is conspicuous next to destructiveHint=false.

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?

Three sentences, front-loaded with the core action and then the verification contract; little filler. The final sentence ('cannot smash V0 or A0 for the unused kind') is jargon-heavy and takes effort to parse, which costs a point.

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?

Output schema exists so return values need not be explained, and the verification semantics are covered. Missing for a 7-parameter mutation tool is any guidance on choosing tracks, the meaning of auto_empty in the flow, idempotency expectations, or when to prefer a sibling edit tool.

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%, including a rich idempotency_key explanation and the auto_empty audio_track_index mode, so the schema carries parameter semantics. The description mentions none of the parameters (item_id, track_index, audio_track_index, start_seconds) and only obliquely gestures at track landing, so baseline 3 applies.

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 and resource: overwrite a project item onto validated timeline tracks at a requested time, plus a verification step. It is clear what the tool does, but it never names or distinguishes itself from near neighbors such as add_to_timeline, overwrite_from_source, or replace_clip, so sibling disambiguation is left to the agent.

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

Usage Guidelines2/5

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

There is no explicit when-to-use guidance, no alternative named, and no prerequisites (target track selection, sequence must be active, item must be a project item). The discussion of video-only/audio-only items explains a behavioral edge case rather than when an agent should pick this tool over add_to_timeline or overwrite_from_source.

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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