stitch-mcp-stdio

upload_design_md

Destructive

Upload a DESIGN.md file to a Stitch project so a design system can be generated from it. Turns design documentation into a functional design system.

Instructions

Uploads DESIGN.md to a Stitch project. Use this tool when the user wants to create a design system from a DESIGN.md file.

Instructions for Tool Call:

Call create_design_system_from_design_md tool immediately after this tool to create the design system from the uploaded DESIGN.md, and display the design system in the UI.

Input Schema

TableJSON Schema

Name	Required	Description	Default
`projectId`	Yes	Required. The project ID to upload the DESIGN.md to, example: '4044680601076201931', without the `projects/` prefix.
`designMdBase64`	Yes	Required. The base64-encoded DESIGN.md content. The decoded content must be valid UTF-8; uploads with invalid UTF-8 bytes will be rejected. Run `base64 -w 0 ` to get the base64-encoded string.

Output Schema

TableJSON Schema

Name	Required	Description
`x`	No	Optional. The x position of the screen.
`y`	No	Optional. The y position of the screen.
`id`	No	Optional. The screen instance id.
`type`	No	Optional. The type of screen instance.
`label`	No	Optional. The screen label.
`width`	No	Optional. The screen width.
`height`	No	Optional. The screen height.
`hidden`	No	Optional. User driven action hiding screen from the canvas.
`groupId`	No	Optional. Group identifier for Genie Agent output grouping. Screens with the same groupId are rendered and interact as a group.
`groupName`	No	Optional. Human-readable name for the group (e.g., "Warm Minimalism", "Ethereal Glow").
`isResized`	No	Optional. Whether this screen has been resized by the user.
`isFavourite`	No	Optional. Whether this screen is marked as a favourite by the user.
`needsLayout`	No	Optional. Whether this screen instance needs frontend layout positioning. Set by the PostProcessor when auto-linking screens that the agent generated but the frontend has not yet positioned on the canvas.
`sourceAsset`	No	Optional. The resource name of the source asset. Format: assets/{asset}. Only one of the following fields should be set: this field, sourceScreen, textContent.
`textContent`	No	Optional. Text content for TEXT_INSTANCE nodes. Only one of the following fields should be set: this field, sourceScreen, sourceAsset.
`sourceScreen`	No	Optional. The resource name of the source screen. Format: projects/{project}/screens/{screen}. Only one of the following fields should be set: this field, sourceAsset, textContent.
`variantScreenInstance`	No	Optional. The variant Screen Instance.

Schema Changelog

Changes observed during successful MCP inspections.

First observedv1.0.0Sep 20, 2026

TDQS

A4.3/5.0

Behavior3/5

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

Annotations already mark the tool as destructive, and the description does not contradict that. It adds the valuable workflow constraint that this tool must be followed by `create_design_system_from_design_md`, but it does not disclose what the destructive effect impacts (e.g., overwriting an existing DESIGN.md), so it only partially exceeds what annotations provide.

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 compact, with a front-loaded purpose sentence and a clearly separated bolded instruction block. Every sentence contributes necessary guidance, with no padding.

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

Completeness5/5

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

For a two-parameter upload tool with full schema coverage and an output schema present, the description supplies the purpose, the trigger condition, and the mandatory follow-up call. Nothing essential for correct invocation and orchestration is missing.

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 parameter schema fully documents both `projectId` and `designMdBase64`, including format and base64 requirements. The description itself only reinforces that the content is DESIGN.md, so it adds little beyond the schema, meriting the baseline score.

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 opens with 'Uploads DESIGN.md to a Stitch project,' naming a specific verb and resource. It also clarifies when to use it and references the sibling `create_design_system_from_design_md` as the follow-up, making it distinguishable from the related creation tool.

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

Usage Guidelines5/5

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

It explicitly states 'Use this tool when the user wants to create a design system from a DESIGN.md file' and then mandates calling `create_design_system_from_design_md` immediately afterward. This gives the agent both a clear trigger condition and the required next step.

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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