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Select ellipse

gimp_select_ellipse

Select an antialiased ellipse within a defined rectangle and combine it with the current selection using replace, add, subtract, or intersect.

Instructions

Select the ellipse inscribed in the rectangle (x, y, width, height), antialiased, combined with the current selection.

Tool call template

Replace each placeholder with a value matching the input schema. Only required parameters are included; add optional parameters as needed.

{
  "id": 1,
  "jsonrpc": "2.0",
  "method": "tools/call",
  "params": {
    "arguments": {
      "image": "<image>",
      "x": "<x>",
      "y": "<y>",
      "width": "<width>",
      "height": "<height>"
    },
    "name": "gimp_select_ellipse"
  }
}

Input Schema

NameRequiredDescriptionDefault
xYes
yYes
imageYesImage id from gimp_status, e.g. 'image:1@a1b2c3d4'.
widthYes
heightYes
featherNoFeather radius in pixels (0 = hard edge).
operationNoHow the new shape combines with the current selection.replace

Output Schema

NameRequiredDescriptionDefault
emptyYes
imageYes
boundsYesBounding box of the selection, clipped to the canvas; null when empty.
containsNoWhether (probe_x, probe_y) is selected (> 50%), when a probe point was given.

Schema Changelog

Changes observed during successful MCP inspections.

  1. First observedv0.1.0

TDQS

A3.7/5.0
Behavior3/5

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

The annotations already establish that this is not read-only, not destructive, and not open-world. The description adds useful behavior by noting antialiasing and combination with the current selection, but it does not clarify how the operation modes or feather radius affect the selection result.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Conciseness5/5

Is the description appropriately sized, front-loaded, and free of redundancy?

The description is a single front-loaded sentence with no redundant wording. Every phrase contributes to identifying the shape, its geometry, and its rendering behavior.

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?

The tool has a moderate schema with selection-combination modes and feathering, plus an output schema. The description covers the ellipse geometry and antialiasing, but it leaves the operation-mode behavior and selection-state effects underexplained.

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?

The description adds meaning to x, y, width, and height by explaining that they define the rectangle in which the ellipse is inscribed. It does not describe feather or operation, although those parameters do have schema descriptions.

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?

The description states a specific verb and resource: selecting an ellipse. It also defines the geometry as an ellipse inscribed in the given rectangle, which clearly distinguishes it from gimp_select_rectangle.

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?

Usage is implied by the explicit 'Select the ellipse' action, but the description does not say when to use this instead of gimp_select_rectangle, gimp_modify_selection, or gimp_get_selection. There are no explicit exclusions or alternative-routing instructions.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.