This record as markdown: /tools/easehee-rhino-mcp/rhino-sphere.md
What rhino_sphere does on Rhino
AI agents use rhino_sphere 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_sphere is rated Medium
This tool creates geometry objects (spheres) in Rhino, which modifies the 3D model state reversibly. It is Write-category because: (1) it creates/adds new data (geometry); (2) the action is reversible (objects can be deleted); (3) it does not execute arbitrary code, delete data irreversibly, or move money.
From the tool's definition Tool name 'rhino_sphere' combined with description 'Add a sphere primitive' indicates creation of geometry in Rhino.
Attacks that exploit this kind of access
The rule that runs rhino_sphere 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_sphere, this is the rule to start with:
rhino_sphere 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_sphere call is checked against it from then on.
Questions about rhino_sphere
Add a sphere primitive. 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_sphere: 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_sphere 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_sphere 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_sphere. 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_sphere 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.
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