gh_cluster_expand
Expand a cluster back into its constituent components.
This record as markdown: /tools/easehee-rhino-mcp/gh-cluster-expand.md
What gh_cluster_expand does on Rhino
AI agents use gh_cluster_expand 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 gh_cluster_expand is rated Medium
The tool transforms a clustered group back into individual components—a state modification but not destructive (expansion is undoable by re-clustering). No data is deleted irreversibly, no external code is executed, and no read-only retrieval occurs. This is a Write operation with low severity since Grasshopper projects are typically design documents with low blast radius if modified unexpectedly.
From the tool's definition gh_cluster_expand modifies the state of a Grasshopper definition by expanding a cluster into component parts, which is a reversible structural change to the graph.
Attacks that exploit this kind of access
The rule that runs gh_cluster_expand 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 gh_cluster_expand, this is the rule to start with:
gh_cluster_expand 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 gh_cluster_expand call is checked against it from then on.
Questions about gh_cluster_expand
Expand a cluster back into its constituent components. 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 gh_cluster_expand: 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.
gh_cluster_expand 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 gh_cluster_expand 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 gh_cluster_expand. 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.
gh_cluster_expand 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