excalidraw-editor-mcp

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Replace Excalidraw canvas

replace_canvas

Replace an existing Excalidraw canvas with a complete new document using atomic revision-controlled updates to prevent conflicts and maintain data integrity.

Instructions

Validates, restores, and atomically replaces one complete standard document.

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": {
      "projectPath": "<projectPath>",
      "canvasPath": "<canvasPath>",
      "baseRevision": "<baseRevision>",
      "mutationId": "<mutationId>",
      "document": "<document>"
    },
    "name": "replace_canvas"
  }
}

Input Schema

Name	Required	Description
`document`	Yes
`canvasPath`	Yes	Full workspace-relative canvas path under projectPath, for example designs/m3/main.excalidraw. Never pass only main.excalidraw.
`mutationId`	Yes
`projectPath`	Yes	Full workspace-relative project path, for example designs/m3.
`baseRevision`	Yes

Schema Changelog

Changes observed during successful MCP inspections.

First observedv0.0.0Sep 7, 2026

TDQS

C2.3/5.0

Behavior2/5

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

With no annotations, the description carries the full burden. It mentions 'atomically replaces' which implies destructive behavior, but does not state that the existing canvas is overwritten, what happens on validation failure, whether changes are reversible, or what 'restores' means. It lacks essential details about side effects and failure modes.

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

Conciseness3/5

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

The description is a single concise sentence, but it is vague and uses jargon like 'standard document' without elaboration. It is not front-loaded with the most critical information (what exactly is replaced and the atomic guarantee). It is concise but not particularly well-structured or helpful.

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

Completeness1/5

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

Given the complexity (5 required params, nested document object, no output schema, no annotations), the description is grossly inadequate. It fails to explain the atomic replacement semantics, how baseRevision is used for optimistic concurrency, what mutationId is for, or what happens to attached files and appState. An agent cannot safely invoke this tool without additional context.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Parameters2/5

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema coverage is only 40% (projectPath and canvasPath have descriptions). The description adds no parameter-specific information. It does not explain the role of baseRevision (concurrency control), mutationId (idempotency), or the structure of document. With low schema coverage, the description should compensate, but it does not.

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

Purpose3/5

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

The description states a verb (replaces) and a resource (standard document), but 'standard document' is ambiguous and doesn't clearly tie to an Excalidraw canvas until the title. It also adds 'validates, restores' without explaining what these mean. It does not distinguish from sibling tools like apply_canvas_changes or push_canvas, which also modify canvas content.

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 is provided on when to use this tool versus alternatives. There is no mention of atomic replacement being preferred for full-document swaps, nor any exclusions (e.g., partial updates). The agent is left to infer use cases from the name alone.

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