AI agents use clear_frame to create or update resources in Piskel MCP Server — usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your Piskel MCP Server environment.
Clearing a frame removes all pixel data from that frame, which is a modification of existing data. While destructive within the frame, it operates on a project that can be recreated and does not delete the project itself. It is reversible in the context of a broader project (e.g., undo functionality or recreating the frame), so Write is more appropriate than Destructive.
From the tool's definition Clear all pixels in a frame
Risk signalsBulk/mass operation — affects multiple targets
Documented attack patterns abuse exactly the kind of access clear_frame gives an agent:
PolicyLayer is an MCP gateway — it sits between your AI agents and Piskel MCP Server, and nothing reaches the server without passing your rules. This is the rule we recommend for clear_frame:
{
"version": "1",
"default": "deny",
"tools": {
"clear_frame": {
"limits": [
{
"counter": "clear_frame_rate",
"window": "minute",
"max": 30,
"scope": "grant"
}
]
}
}
}clear_frame 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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Clear all pixels in a frame. It is categorised as a Write tool in the Piskel MCP Server MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.
Register the Piskel MCP Server MCP server in PolicyLayer and add a rule for clear_frame: 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 Piskel MCP Server. Nothing to install.
clear_frame 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 clear_frame 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 clear_frame. 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.
clear_frame is provided by the Piskel MCP Server MCP server (yafeiaa/piskel-mcp-server). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Start from Piskel MCP Server, add the rest of your stack, and see everything your agents can call. Then put policy on all of it.
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45 Piskel MCP Server tools catalogued and risk-classified — across an index of 43,000+ MCP servers.