Remove the last N blocks YOU placed (your own recent ADD brushes), by reading your agent_brush_log and issuing op:"remove" at each cell. Default n=1, max 20. Only reverses ADDs (a prior remove is skipped). Needs your token to allow destructive edits; without it each cell comes back reason:"would-...
Part of the Space0 server.
Free to start. No card required.
AI agents may call undo_last_brushes to permanently remove or destroy resources in Space0. Without a policy, an autonomous agent could delete critical data in a loop with no way to undo the damage. PolicyLayer blocks destructive tools by default and requires explicit human approval before enabling them.
Without a policy, an AI agent could call undo_last_brushes in a loop, permanently destroying resources in Space0. There is no undo for destructive operations. PolicyLayer blocks this tool by default and only allows it when a human explicitly approves the action.
Destructive tools permanently remove data. Block by default. Only enable with explicit approval workflows.
{
"version": "1",
"default": "deny",
"hide": [
"undo_last_brushes"
]
}See the full Space0 policy for all 60 tools.
These attack patterns abuse exactly the kind of access undo_last_brushes gives an agent. Each links to the full case and the policy that stops it:
Other destructive tools across the catalogue. The same approach applies to each: deny by default, or require human approval.
Remove the last N blocks YOU placed (your own recent ADD brushes), by reading your agent_brush_log and issuing op:"remove" at each cell. Default n=1, max 20. Only reverses ADDs (a prior remove is skipped). Needs your token to allow destructive edits; without it each cell comes back reason:"would-remove-denied"/"out-of-claim". The cleaner fix for a bad build is build({dry_run:true}) BEFORE committing; undo_last_brushes is the recovery when you already placed something wrong. Returns { undone, failed, failed_cells }.. It is categorised as a Destructive tool in the Space0 MCP Server, which means it can permanently delete or destroy data. Block by default and require explicit approval.
Register the Space0 MCP server in PolicyLayer and add a rule for undo_last_brushes: 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 Space0. Nothing to install.
undo_last_brushes is a Destructive tool with critical risk. Critical-risk tools should be blocked by default and only enabled with explicit human approval.
Yes. Add a rate_limit block to the undo_last_brushes 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 undo_last_brushes. 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.
undo_last_brushes is provided by the Space0 MCP server (https://mcp.0.space/mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Deterministic rules across all 60 Space0 tools. Per-identity grants. Full audit log. Live in minutes. Nothing to install.
Free to start. No card required.
4,600+ MCP servers and 31,000+ tools scanned and risk-classified.