This record as markdown: /tools/easehee-rhino-mcp/rhino-helix.md
What rhino_helix does on Rhino
AI agents use rhino_helix to create or update resources in Rhino, usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your Rhino environment.
Why rhino_helix is rated Medium
This tool creates new geometry (a helix curve) within Rhino, which is a reversible write operation. It does not retrieve data (Read), execute arbitrary code (Execute), permanently delete anything (Destructive), or involve financial transactions (Financial).
From the tool's definition The tool 'rhino_helix' performs an 'Add a helix sampled into a NURBS curve' operation. The verb 'Add' indicates creation of geometry, which is a write operation that modifies the Rhino model by creating new geometry objects.
Attacks that exploit this kind of access
The rule that runs rhino_helix safely
PolicyLayer is an MCP gateway: it sits between your AI agents and Rhino, and checks every tool call against a rule you set before the call runs. Nothing changes on the server itself. For rhino_helix, this is the rule to start with:
rhino_helix 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.
The button opens the PolicyLayer dashboard: create your workspace, connect Rhino, apply this rule, and every rhino_helix call is checked against it from then on.
Questions about rhino_helix
Add a helix sampled into a NURBS curve. It is categorised as a Write tool in the Rhino MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.
Register the Rhino MCP server in PolicyLayer and add a rule for rhino_helix: 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 Rhino. Nothing to install.
rhino_helix 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 rhino_helix 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 rhino_helix. 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.
rhino_helix is provided by the Rhino MCP server (easehee/rhino-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
More on Rhino, and thousands of servers like it.
This server
Across the catalogue