AI agents use update_slab to create or update resources in IFC Bonsai MCP — usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your IFC Bonsai MCP environment.
The tool modifies/updates data (a slab in an IFC model) reversibly within the Blender environment. It is Write-category because slabs can be re-edited or reverted, not Destructive. Severity is medium because incorrect slab updates could corrupt building models but within a sandboxed design tool.
From the tool's definition Tool name 'update_slab' indicates modification of an existing slab element within an IFC model. The server context describes 'create, and edit IFC models' and sibling tools include 'create_slab', confirming this tool modifies IFC building components.
Documented attack patterns abuse exactly the kind of access update_slab gives an agent:
PolicyLayer is an MCP gateway — it sits between your AI agents and IFC Bonsai MCP, and nothing reaches the server without passing your rules. This is the rule we recommend for update_slab:
{
"version": "1",
"default": "deny",
"tools": {
"update_slab": {
"limits": [
{
"counter": "update_slab_rate",
"window": "minute",
"max": 30,
"scope": "grant"
}
]
}
}
}update_slab 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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update_slab. It is categorised as a Write tool in the IFC Bonsai MCP MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.
Register the IFC Bonsai MCP server in PolicyLayer and add a rule for update_slab: 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 IFC Bonsai MCP. Nothing to install.
update_slab 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 update_slab 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 update_slab. 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.
update_slab is provided by the IFC Bonsai MCP server (show2instruct/ifc-bonsai-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Deterministic rules across all 52 IFC Bonsai MCP tools. Per-identity grants. Full audit log. Live in minutes. Nothing to install.
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52 IFC Bonsai MCP tools catalogued and risk-classified — across an index of 42,500+ MCP servers.