AI agents use draft_shapestring to create or update resources in FreeCAD Robust MCP Server — usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your FreeCAD Robust MCP Server environment.
FreeCAD geometry creation tools modify the document model by adding new shapes or geometry elements. This is reversible (objects can be deleted, undo is available), so it classifies as Write rather than Destructive or Execute. However, description is empty, reducing confidence.
From the tool's definition Tool name 'draft_shapestring' indicates shape/geometry creation in FreeCAD's Draft workbench. Sibling tools like 'add_sketch_arc', 'add_sketch_circle', 'add_sketch_line' all create or modify 2D/3D geometry.
Documented attack patterns abuse exactly the kind of access draft_shapestring gives an agent:
PolicyLayer is an MCP gateway — it sits between your AI agents and FreeCAD Robust MCP Server, and nothing reaches the server without passing your rules. This is the rule we recommend for draft_shapestring:
{
"version": "1",
"default": "deny",
"tools": {
"draft_shapestring": {
"limits": [
{
"counter": "draft_shapestring_rate",
"window": "minute",
"max": 30,
"scope": "grant"
}
]
}
}
}draft_shapestring 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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draft_shapestring. It is categorised as a Write tool in the FreeCAD Robust MCP Server MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.
Register the FreeCAD Robust MCP Server MCP server in PolicyLayer and add a rule for draft_shapestring: 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 FreeCAD Robust MCP Server. Nothing to install.
draft_shapestring 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 draft_shapestring 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 draft_shapestring. 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.
draft_shapestring is provided by the FreeCAD Robust MCP Server MCP server (spkane/freecad-addon-robust-mcp-server). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Deterministic rules across all 152 FreeCAD Robust MCP Server tools. Per-identity grants. Full audit log. Live in minutes. Nothing to install.
Free to start. No card required.
152 FreeCAD Robust MCP Server tools catalogued and risk-classified — across an index of 42,500+ MCP servers.