Medium Risk

add_elements

Add multiple Excalidraw elements to the canvas.\n\n

How to control add_elements ↓

AI agents use add_elements to create or update resources in Excalidraw MCP Server — usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your Excalidraw MCP Server environment.

Medium Risk

The tool creates or adds new elements to Excalidraw diagrams, which is a Write operation—data is being created/modified but remains reversible. The sibling tools show delete_element and update_element exist separately, confirming add_elements performs creation only.

From the tool's definition Tool name 'add_elements' and description 'Add multiple Excalidraw elements to the canvas' indicate creation of new diagram content. This is a reversible modification operation.

Documented attack patterns abuse exactly the kind of access add_elements gives an agent:

PolicyLayer is an MCP gateway — it sits between your AI agents and Excalidraw MCP Server, and nothing reaches the server without passing your rules. This is the rule we recommend for add_elements:

policy.json
{
  "version": "1",
  "default": "deny",
  "tools": {
    "add_elements": {
      "limits": [
        {
          "counter": "add_elements_rate",
          "window": "minute",
          "max": 30,
          "scope": "grant"
        }
      ]
    }
  }
}

add_elements stays usable, but capped — an agent stuck in a loop can't make hundreds of changes a minute. Everything else on the server is denied unless you say otherwise.

  1. Create a free account and register Excalidraw MCP Server — nothing to install.
  2. Add this policy — paste it, or build it visually.
  3. Point your MCP client (Claude, Cursor, anything) at your gateway URL.
LIMIT THIS TOOL →

Free to start. No card required.

Go deeper

What does the add_elements tool do? +

Add multiple Excalidraw elements to the canvas.\n\n. It is categorised as a Write tool in the Excalidraw MCP Server MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on add_elements? +

Register the Excalidraw MCP Server MCP server in PolicyLayer and add a rule for add_elements: allow, deny, rate-limit, or require approval. Point your MCP client at the PolicyLayer proxy URL and the rule is enforced on every call, before it reaches Excalidraw MCP Server. Nothing to install.

What risk level is add_elements? +

add_elements is a Write tool with medium risk. Write tools should be rate-limited to prevent accidental bulk modifications.

Can I rate-limit add_elements? +

Yes. Add a rate_limit block to the add_elements rule in your PolicyLayer policy. For example, setting max: 10 and window: 60 limits the tool to 10 calls per minute. Rate limits are tracked per agent session and reset automatically.

How do I block add_elements completely? +

Set action: deny in the PolicyLayer policy for add_elements. The AI agent will receive a policy violation error and cannot call the tool. You can also include a reason field to explain why the tool is blocked.

What MCP server provides add_elements? +

add_elements is provided by the Excalidraw MCP Server MCP server (scofieldfree/excalidraw-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.

Enforce policy on every Excalidraw MCP Server tool call.

Deterministic rules across all 11 Excalidraw MCP Server tools. Per-identity grants. Full audit log. Live in minutes. Nothing to install.

Free to start. No card required.

11 Excalidraw MCP Server tools catalogued and risk-classified — across an index of 42,500+ MCP servers.

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