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Generate object composite

generate_object_composite

Generate an object composite image by placing a source object into a background, returning Adobe output URLs; set wait=false for an async job.

Instructions

Generate object composite. Consumes Firefly Services credits. Returns Adobe output URLs. Set wait=false to return an async job.

Input Schema

Name	Required	Description
`n`	No	Compatibility alias for numVariations. Do not supply both.
`mask`	No	Selected areas of a background image that Firefly uses to fill the source image.
`size`	No	The desired width and height for the final image in pixels. The supported sizes for the output images are: Square (1:1) - width 2048px, height 2048px Square (1:1) - width 1024px, height 1024px Landscape (4:3) - width 2304px, height 1792px Portrait (3:4) - width 1792px, height 2304px Widescreen (16:9) - width 2688px, height 1536px (7:4) - width 1344px, height 768px (9:7) - width 1152px, height 896px (7:9) - width 896px, height 1152px .
`wait`	No	Wait for completion, default true. Set false to return the job immediately.
`image`	No	The image to expand. Use a URL or an uploadID as the source for the image. Firefly only allows these listed domains for input URLs in the request: amazonaws.com windows.net dropboxusercontent.com storage.googleapis.com .
`seeds`	No	Array of seed image IDs. These reference images help ensure consistent image generation across multiple API calls. If specified along with numVariations, the number of seeds must equal numVariations.
`style`	No
`width`	No	Compatibility alias: provide together with height instead of size.
`height`	No	Compatibility alias: provide together with width instead of size.
`prompt`	Yes	A text prompt up to 1024 characters. The longer the prompt the better Firefly performs.
`confirm`	No	Set true only when the user asked for exactly this action.
`maskUrl`	No	Compatibility URL alias for mask.source.url.
`download`	No	Download completed media to FIREFLY_OUTPUT_DIR, default false. Requires wait=true.
`imageUrl`	No	Compatibility URL alias for image.source.url.
`placement`	No	The position of the source image after Firefly adjusts it. The value describes the horizontal and vertical placement and dimensions of the image in the output. Note you cannot use placement for source images when you also apply a mask image.
`contentClass`	No	The content class of the image.
`numVariations`	No	Generate this number of variations. Defaults to the number of seed images, or to 1 if you do not specify seeds.

Schema Changelog

Changes observed during successful MCP inspections.

Changed30 schema fields changedv3.0.0Oct 6, 2026
- addedInput schema / $defs
```
Added value: +{
+  "url": {
+    "description": "The pre-signed URL of an uploaded file. Use a URL or an `uploadID` as the source for the image. Firefly only allows these listed domains in the request: amazonaws.com windows.net dropboxusercontent.com storage.googleapis.com .",
+    "format": "uri",
+    "maxLength": 2083,
+    "minLength": 1,
+    "type": "string"
+  }
+}
```
- changedInput schema / properties / confirm / description
```
Previous value: -"Must be true to spend Firefly Services credits for the operation the user requested."New value: +"Set true only when the user asked for exactly this action."
```
- changedInput schema / properties / image / properties / mask / properties / uploadId / format
```
Previous value: -"uuid4"New value: +"uuid"
```
- addedInput schema / properties / image / properties / mask / properties / url / $ref
```
Added value: +"#/$defs/url"
```
- removedInput schema / properties / image / properties / mask / properties / url / description
```
Removed value: -"The pre-signed URL of an uploaded file. Use a URL or an `uploadID` as the source for the image. Firefly only allows these listed domains in the request: amazonaws.com windows.net dropboxusercontent.com storage.googleapis.com ."
```
- removedInput schema / properties / image / properties / mask / properties / url / format
```
Removed value: -"uri"
```
- removedInput schema / properties / image / properties / mask / properties / url / maxLength
```
Removed value: -2083
```
- removedInput schema / properties / image / properties / mask / properties / url / minLength
```
Removed value: -1
```
- removedInput schema / properties / image / properties / mask / properties / url / type
```
Removed value: -"string"
```
- changedInput schema / properties / image / properties / source / properties / uploadId / format
```
Previous value: -"uuid4"New value: +"uuid"
```
- addedInput schema / properties / image / properties / source / properties / url / $ref
```
Added value: +"#/$defs/url"
```
- removedInput schema / properties / image / properties / source / properties / url / description
```
Removed value: -"The pre-signed URL of an uploaded file. Use a URL or an `uploadID` as the source for the image. Firefly only allows these listed domains in the request: amazonaws.com windows.net dropboxusercontent.com storage.googleapis.com ."
```
- removedInput schema / properties / image / properties / source / properties / url / format
```
Removed value: -"uri"
```
- removedInput schema / properties / image / properties / source / properties / url / maxLength
```
Removed value: -2083
```
- removedInput schema / properties / image / properties / source / properties / url / minLength
```
Removed value: -1
```
- removedInput schema / properties / image / properties / source / properties / url / type
```
Removed value: -"string"
```
- changedInput schema / properties / mask / properties / source / properties / uploadId / format
```
Previous value: -"uuid4"New value: +"uuid"
```
- addedInput schema / properties / mask / properties / source / properties / url / $ref
```
Added value: +"#/$defs/url"
```
- removedInput schema / properties / mask / properties / source / properties / url / description
```
Removed value: -"The pre-signed URL of an uploaded file. Use a URL or an `uploadID` as the source for the image. Firefly only allows these listed domains in the request: amazonaws.com windows.net dropboxusercontent.com storage.googleapis.com ."
```
- removedInput schema / properties / mask / properties / source / properties / url / format
```
Removed value: -"uri"
```
- removedInput schema / properties / mask / properties / source / properties / url / maxLength
```
Removed value: -2083
```
- removedInput schema / properties / mask / properties / source / properties / url / minLength
```
Removed value: -1
```
- removedInput schema / properties / mask / properties / source / properties / url / type
```
Removed value: -"string"
```
- changedInput schema / properties / style / properties / imageReference / properties / source / properties / uploadId / format
```
Previous value: -"uuid4"New value: +"uuid"
```
- addedInput schema / properties / style / properties / imageReference / properties / source / properties / url / $ref
```
Added value: +"#/$defs/url"
```
- removedInput schema / properties / style / properties / imageReference / properties / source / properties / url / description
```
Removed value: -"The pre-signed URL of an uploaded file. Use a URL or an `uploadID` as the source for the image. Firefly only allows these listed domains in the request: amazonaws.com windows.net dropboxusercontent.com storage.googleapis.com ."
```
- removedInput schema / properties / style / properties / imageReference / properties / source / properties / url / format
```
Removed value: -"uri"
```
- removedInput schema / properties / style / properties / imageReference / properties / source / properties / url / maxLength
```
Removed value: -2083
```
- removedInput schema / properties / style / properties / imageReference / properties / source / properties / url / minLength
```
Removed value: -1
```
- removedInput schema / properties / style / properties / imageReference / properties / source / properties / url / type
```
Removed value: -"string"
```
First observedv2.0.0Oct 2, 2026

TDQS

C2.8/5.0

Behavior4/5

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

Annotations declare readOnlyHint=false, openWorldHint=true, idempotentHint=false, destructiveHint=false but say nothing about cost or response shape. The description adds two genuinely useful facts beyond that: it consumes Firefly Services credits, and it returns Adobe output URLs, plus the async escape hatch via wait=false. It does not contradict the annotations, but it omits auth/rate-limit context.

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?

Four short, front-loaded sentences with no padding or repetition. It is efficient, though its brevity is partly under-specification rather than disciplined concision.

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

Completeness2/5

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

For a 17-parameter composite tool with deep nesting, a credits cost, an async mode, and three near-identical composite siblings, the description is far too thin. It does not explain what distinguishes 'object composite' from precise/adaptive compositing, nor how placement/mask interact, which is left entirely to the schema.

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 94%, so all 17 parameters (including the many compatibility aliases, size presets, and the deprecated image.mask) are already documented in the schema. The description mentions only wait=false, adding nothing further. Baseline 3 is appropriate when the schema carries the parameter burden.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Purpose2/5

Does the description clearly state what the tool does and how it differs from similar tools?

The opening sentence 'Generate object composite' is a verbatim restatement of the tool title/name, adding no distinguishing detail. With siblings like precise_composite and adaptive_composite in the same family, the description gives an agent no basis to tell them apart. This is essentially tautological.

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?

No guidance on when to use this tool versus precise_composite, adaptive_composite, or generative_fill. The only operational note ('Set wait=false to return an async job') is a behavior hint, not a usage condition. The agent must infer routing entirely from the name and schema.

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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Generate object composite

Instructions

Input Schema

Schema Changelog

TDQS

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