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generate_variants

Create multiple design variations for an existing screen by specifying the aspects to vary (color, layout, images, fonts, text) and the creative range, guided by a prompt.

Instructions

Generate design variants of an existing screen

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": {
      "projectId": "<projectId>",
      "screenId": "<screenId>",
      "prompt": "<prompt>"
    },
    "name": "generate_variants"
  }
}

Input Schema

Name	Required	Description	Default
`prompt`	Yes	Prompt guiding the variants (e.g., 'Try different color schemes')
`aspects`	No	Aspects of the design to vary
`screenId`	Yes	The ID of the screen to generate variants from
`projectId`	Yes	The ID of the project containing the screen
`variantCount`	No	Number of variants to generate (1-5)
`creativeRange`	No	How different the variants should be	EXPLORE

Schema Changelog

Changes observed during successful MCP inspections.

First observedv1.0.6Aug 1, 2026

TDQS

B3.2/5.0

Behavior2/5

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

No annotations are provided, so the description must carry the full burden of disclosing behavioral traits. It only says 'generate variants' without mentioning whether this creates new records, mutates existing data, returns output, or has side effects. This leaves the agent with little behavioral understanding.

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?

A single, front-loaded sentence that communicates the core function without any filler or redundancy. It is appropriately concise for the level of schema detail provided.

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 tool with six parameters and no output schema, the description is too thin. It fails to explain what 'variants' means operationally—whether they are saved, returned as code, or displayed—especially given the presence of sibling tools like generate_and_fetch_code. The schema covers parameters but not the overall tool behavior.

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 input schema provides full descriptions for all six parameters (100% coverage), so the description does not need to explain parameter semantics. The description adds no additional parameter context, but the baseline of 3 is appropriate given complete schema coverage.

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?

The description clearly states the verb 'Generate' and the resource 'design variants of an existing screen', making the core purpose obvious. It is distinct from sibling tools like generate_screen, but it does not explicitly name or contrast with alternatives, so it falls short of a 5.

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?

The phrase 'existing screen' implies that this tool is for modifying or branching from an already-created screen, which suggests usage context. However, there is no explicit statement about when to use this tool versus generate_screen, edit_screen, or other siblings.

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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