merge · LocuSync Server MCP: Risk & Policy

WHAT IT DOES

What merge does on LocuSync Server

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

WHY IT NEEDS A POLICY

Why merge needs a policy

The merge operation creates a new combined dataset from multiple inputs, which is a reversible write operation. It does not delete or irreversibly alter the original feature collections, nor does it execute arbitrary code or trigger external side effects.

From the tool's definition Tool description states 'Merge multiple feature collections into one' — this is a data modification operation that combines existing geospatial data structures into a new aggregated form.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

merge Rate-limited

merge 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": {
    "merge": {
      "limits": [
        {
          "counter": "merge_rate",
          "window": "minute",
          "max": 30,
          "scope": "grant"
        }
      ]
    }
  }
}

LIMIT THIS TOOL →

Instant setup, no code required.

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

FAQ

Questions about merge

What does the merge tool do? +

Merge multiple feature collections into one. It is categorised as a Write tool in the LocuSync Server MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on merge? +

Register the LocuSync Server MCP server in PolicyLayer and add a rule for merge: 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 LocuSync Server. Nothing to install.

What risk level is merge? +

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

Can I rate-limit merge? +

Yes. Add a rate_limit block to the merge 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 merge completely? +

Set action: deny in the PolicyLayer policy for merge. 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 merge? +

merge is provided by the LocuSync Server MCP server (matbel91765/gis-mcp-server). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.