lucene_upsert · Mcp Lucene MCP: Risk & Policy

WHAT IT DOES

What lucene_upsert does on Mcp Lucene

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

WHY IT NEEDS A POLICY

Why lucene_upsert needs a policy

This tool creates or modifies documents in a Lucene search index. Upsert operations are reversible writes—documents can be updated or re-indexed. While it modifies data, it does not permanently delete or destroy information. Severity is medium because misuse could corrupt search indices or introduce malicious data into indexed content, but the operation itself is not irreversible.

From the tool's definition Tool is named 'lucene_upsert' and described as 'Upsert documents into Lucene index.' Upsert is a reversible write operation (insert or update).

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

lucene_upsert Rate-limited

lucene_upsert 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": {
    "lucene_upsert": {
      "limits": [
        {
          "counter": "lucene_upsert_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 Mcp Lucene, so you can run agents against it safely.

FAQ

Questions about lucene_upsert

What does the lucene_upsert tool do? +

Upsert documents into Lucene index. It is categorised as a Write tool in the Mcp Lucene MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on lucene_upsert? +

Register the Mcp Lucene MCP server in PolicyLayer and add a rule for lucene_upsert: 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 Mcp Lucene. Nothing to install.

What risk level is lucene_upsert? +

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

Can I rate-limit lucene_upsert? +

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

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

lucene_upsert is provided by the Mcp Lucene MCP server (vivekkumarneu/mcp-lucene-server). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.