Apply a wall, roof, or floor construction to a surface.
AI agents use assign_construction_to_surface to create or update resources in Openstudio — usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your Openstudio environment.
This tool modifies building energy simulation model properties by assigning construction definitions to surfaces. This is a reversible write operation—the construction can be changed or replaced without data loss. It does not delete data (not Destructive), does not execute arbitrary code (not Execute), and does not involve financial transactions (not Financial).
From the tool's definition Tool name 'assign_construction_to_surface' and description 'Apply a wall, roof, or floor construction to a surface' indicate modification of building model properties. The verb 'apply' and 'assign' confirm a write operation that modifies existing model data.
Documented attack patterns abuse exactly the kind of access assign_construction_to_surface gives an agent:
PolicyLayer is an MCP gateway — it sits between your AI agents and Openstudio, and nothing reaches the server without passing your rules. This is the rule we recommend for assign_construction_to_surface:
{
"version": "1",
"default": "deny",
"tools": {
"assign_construction_to_surface": {
"limits": [
{
"counter": "assign_construction_to_surface_rate",
"window": "minute",
"max": 30,
"scope": "grant"
}
]
}
}
}assign_construction_to_surface 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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Apply a wall, roof, or floor construction to a surface. It is categorised as a Write tool in the Openstudio MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.
Register the Openstudio MCP server in PolicyLayer and add a rule for assign_construction_to_surface: 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 Openstudio. Nothing to install.
assign_construction_to_surface 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 assign_construction_to_surface 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 assign_construction_to_surface. 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.
assign_construction_to_surface is provided by the Openstudio MCP server (natlabrockies/openstudio-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Start from Openstudio, add the rest of your stack, and see everything your agents can call. Then put policy on all of it.
Free to start. No card required.
146 Openstudio tools catalogued and risk-classified — across an index of 43,000+ MCP servers.