Remove the background from any image and get a transparent PNG in return. Costs 2 credits per request.
Remove background from any image. Returns transparent PNG. Cost: 2 credits.
| Name | Required | Description | Default |
|---|---|---|---|
| size | No | Output resolution. | auto |
| image_url | Yes | URL to image. |
Changes observed during successful MCP inspections.
v0.3.1Input schema / properties / image_url / descriptionPrevious value: -"URL to the image"New value: +"URL to image."Input schema / properties / sizeAdded value: +{
+ "default": "auto",
+ "description": "Output resolution.",
+ "enum": [
+ "auto",
+ "small",
+ "hd"
+ ],
+ "type": "string"
+}v0.3.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations, the description carries the full disclosure burden. It usefully adds the return format (transparent PNG) and a cost signal (2 credits), which is real behavioral information beyond the schema. However, it omits failure behavior, max input size/resolution constraints, and whether credits are charged on failure.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.
Is the description appropriately sized, front-loaded, and free of redundancy?
Three short sentences with zero filler; the core action is front-loaded and the output format and cost follow immediately. Every sentence earns its place.
Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.
Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?
For a simple two-parameter tool with fully documented schema and no output schema, the description covers action, return type, and cost, which is close to sufficient. It stops short of input constraints or failure modes, but nothing critical to making the call is missing.
Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.
Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?
Schema description coverage is 100%, so both parameters (image_url, size with its enum and default) are already documented in structured form. The description adds nothing parameter-specific, so the baseline of 3 applies.
Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.
Does the description clearly state what the tool does and how it differs from similar tools?
States a specific verb and resource ('Remove background from any image') and names the output artifact ('transparent PNG'), so an agent immediately knows what the tool produces. It does not explicitly distinguish itself from adjacent siblings such as file-convert or images, but the operation is unambiguous.
Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.
Does the description explain when to use this tool, when not to, or what alternatives exist?
The description says the tool works on 'any image' but gives no when-to-use context, no prerequisites (e.g. image accessibility, format limits), and no alternatives among siblings like file-convert or images. Usage has to be inferred entirely from the tool name.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.