This record as markdown: /tools/easehee-rhino-mcp/gh-reset.md
What gh_reset does on Rhino
AI agents call gh_reset to permanently remove resources in Rhino, typically in cleanup and lifecycle workflows. It does its job in a single call, and there is no undo.
Why gh_reset is rated Critical
Resetting the canvas clears all cached solutions on the Grasshopper canvas. This is an irreversible operation that destroys the current working state, removing all cached computation results. While it may not delete persisted files, it irreversibly wipes the in-memory canvas state and cached solutions, which cannot be recovered without re-running the full pipeline.
From the tool's definition Reset the canvas (clear cached solution)
Attacks that exploit this kind of access
The rule that runs gh_reset 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_reset, this is the rule to start with:
gh_reset is removed from the agent's tool list entirely, so the agent never calls it. The rest of the server keeps working.
The button opens the PolicyLayer dashboard: create your workspace, connect Rhino, apply this rule, and every gh_reset call is checked against it from then on.
Questions about gh_reset
Reset the canvas (clear cached solution). It is categorised as a Destructive tool in the Rhino MCP Server, which means it can permanently delete or destroy data. Block by default and require explicit approval.
Register the Rhino MCP server in PolicyLayer and add a rule for gh_reset: 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_reset is a Destructive tool with critical risk. Critical-risk tools should be blocked by default and only enabled with explicit human approval.
Yes. Add a rate_limit block to the gh_reset 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_reset. 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_reset 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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