AI agents use batch_create_elements to create or update resources in Excalidraw — usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your Excalidraw environment.
This tool creates new elements on an Excalidraw canvas—a reversible modification operation. It falls under Write rather than Execute because it adds diagram objects rather than executing arbitrary code or external operations. Severity is medium because batch creation of many elements could clutter or corrupt a diagram, but the action is reversible via delete_element.
From the tool's definition Tool name 'batch_create_elements' indicates creation of multiple diagram elements. The server description states it 'create[s] and manipulate[s] live visual diagrams', and sibling tool 'create_element' is clearly a write operation.
Risk signalsBulk/mass operation — affects multiple targets
Documented attack patterns abuse exactly the kind of access batch_create_elements gives an agent:
PolicyLayer is an MCP gateway — it sits between your AI agents and Excalidraw, and nothing reaches the server without passing your rules. This is the rule we recommend for batch_create_elements:
{
"version": "1",
"default": "deny",
"tools": {
"batch_create_elements": {
"limits": [
{
"counter": "batch_create_elements_rate",
"window": "minute",
"max": 30,
"scope": "grant"
}
]
}
}
}batch_create_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.
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batch_create_elements. It is categorised as a Write tool in the Excalidraw MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.
Register the Excalidraw MCP server in PolicyLayer and add a rule for batch_create_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. Nothing to install.
batch_create_elements is a Write tool with medium risk. Write tools should be rate-limited to prevent accidental bulk modifications.
Yes. Add a rate_limit block to the batch_create_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.
Set action: deny in the PolicyLayer policy for batch_create_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.
batch_create_elements is provided by the Excalidraw MCP server (lesleslie/excalidraw-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Start from Excalidraw, add the rest of your stack, and see everything your agents can call. Then put policy on all of it.
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17 Excalidraw tools catalogued and risk-classified — across an index of 43,000+ MCP servers.