AI agents use add_ev_load 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.
The tool adds an EV (electric vehicle) load component to an OpenStudio energy model. This is a write operation that creates or modifies simulation data reversibly—the addition can be removed or changed without permanent consequences. While it could affect simulation results and energy analysis (hence medium severity), it does not execute arbitrary code, delete data irreversibly, or move money.
From the tool's definition Tool name 'add_ev_load' and server context show this creates or modifies building energy simulation models. The prefix 'add_' indicates creation/modification of model components. Description is empty, which lowers confidence slightly.
Documented attack patterns abuse exactly the kind of access add_ev_load 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 add_ev_load:
{
"version": "1",
"default": "deny",
"tools": {
"add_ev_load": {
"limits": [
{
"counter": "add_ev_load_rate",
"window": "minute",
"max": 30,
"scope": "grant"
}
]
}
}
}add_ev_load 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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add_ev_load. 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 add_ev_load: 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.
add_ev_load 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 add_ev_load 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 add_ev_load. 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.
add_ev_load 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.