AI agents use update_style 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.
This tool modifies existing style data in an IFC model reversibly. It does not delete data (would be Destructive), execute arbitrary code (would be Execute), or move money (would be Financial). The ability to modify styles in architectural/BIM models can affect design outcomes, justifying medium severity.
From the tool's definition Tool name 'update_style' combined with sibling tools like 'create_pbr_style' and 'apply_style_to_object' indicates creation and modification of styles/properties within IFC models. The description is empty, reducing confidence.
Documented attack patterns abuse exactly the kind of access update_style 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_style:
{
"version": "1",
"default": "deny",
"tools": {
"update_style": {
"limits": [
{
"counter": "update_style_rate",
"window": "minute",
"max": 30,
"scope": "grant"
}
]
}
}
}update_style 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_style. 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_style: 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_style 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_style 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_style. 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_style 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.
Free to start. No card required.
52 IFC Bonsai MCP tools catalogued and risk-classified — across an index of 42,500+ MCP servers.