add_sketch_constraint · Solidworks MCP: Risk & Policy

WHAT IT DOES

What add_sketch_constraint does on Solidworks

AI agents use add_sketch_constraint to create or update resources in Solidworks — usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your Solidworks environment.

WHY IT NEEDS A POLICY

Why add_sketch_constraint needs a policy

The tool modifies CAD sketch geometry by adding constraints, which changes the sketch definition but remains reversible. This is a Write operation rather than Execute (which would imply running code/macros) or Destructive (constraints can be removed). The severity is medium because incorrect constraints could corrupt a design requiring rework, but the operation is not inherently irreversible.

From the tool's definition Tool name 'add_sketch_constraint' and description 'Add constraints between sketch entities' indicate modification of sketch data. This creates/modifies constraint relationships within a CAD sketch, which is reversible through undo or constraint deletion.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

add_sketch_constraint Rate-limited

add_sketch_constraint 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.

View as policy code

policy.json

{
  "version": "1",
  "default": "deny",
  "tools": {
    "add_sketch_constraint": {
      "limits": [
        {
          "counter": "add_sketch_constraint_rate",
          "window": "minute",
          "max": 30,
          "scope": "grant"
        }
      ]
    }
  }
}

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Instant setup, no code required.

PolicyLayer is an MCP gateway: every tool call is checked against your rule before it reaches Solidworks, so you can run agents against it safely.

FAQ

Questions about add_sketch_constraint

What does the add_sketch_constraint tool do? +

Add constraints between sketch entities. It is categorised as a Write tool in the Solidworks MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on add_sketch_constraint? +

Register the Solidworks MCP server in PolicyLayer and add a rule for add_sketch_constraint: 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 Solidworks. Nothing to install.

What risk level is add_sketch_constraint? +

add_sketch_constraint is a Write tool with medium risk. Write tools should be rate-limited to prevent accidental bulk modifications.

Can I rate-limit add_sketch_constraint? +

Yes. Add a rate_limit block to the add_sketch_constraint 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.

How do I block add_sketch_constraint completely? +

Set action: deny in the PolicyLayer policy for add_sketch_constraint. 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.

What MCP server provides add_sketch_constraint? +

add_sketch_constraint is provided by the Solidworks MCP server (solidworks-mcp-server). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.