refresh_index

THE RISK

High Risk

Why refresh_index needs a policy

This tool initiates a computational operation that modifies system state (the index) and has side effects (I/O, CPU usage, potential blocking). While not destructive (the operation is reversible—a subsequent refresh recovers previous state), it is Execute-class because it triggers an external process.

From the tool's definition Tool performs a 're-scan of the Maven repository' and 're-index[es] all artifacts' — actions that trigger external operations (file system scanning, index rebuilding) whose effects depend on context (repository state, indexing performance, storage).

Documented attack patterns abuse exactly the kind of access refresh_index gives an agent:

POLICY

How to control refresh_index

PolicyLayer is an MCP gateway — it sits between your AI agents and Maven Indexer, and nothing reaches the server without passing your rules. This is the rule we recommend for refresh_index:

policy.json

{
  "version": "1",
  "default": "deny",
  "tools": {
    "refresh_index": {
      "limits": [
        {
          "counter": "refresh_index_rate",
          "window": "minute",
          "max": 10,
          "scope": "grant"
        }
      ]
    }
  }
}

refresh_index stays usable, but rate-capped — a runaway agent can't fire it dozens of times a minute. Everything else on the server is denied unless you say otherwise.

Create a free account and register Maven Indexer — nothing to install.
Add this policy — paste it, or build it visually.
Point your MCP client (Claude, Cursor, anything) at your gateway URL.

RATE-LIMIT THIS TOOL →

Free to start. No card required.

EXPLORE

Related tools and policies

More Maven Indexer tools

Read get_class_details Retrieve the source code for a class from the local Maven/Gradle cache (containing interna Read search_artifacts Search for internal company artifacts and libraries in the local Maven repository and Grad Read search_classes Search for Java classes in internal company libraries found in the local Maven/Gradle cach Read search_implementations Search for internal implementations of an interface or base class. This is particularly us Read search_resources Search for resources (non-class files) inside JARs, such as properties files, XML configs,

All 6 Maven Indexer tools →

Execute tools on other servers

Android Forensics ADB MCP Server adb_shell_command EMBA-MCP run_emba_scan Frida Game Hacking MCP remove_breakpoint Procmon request_elevation

Go deeper

High-risk tools in Maven Indexer → Every high-risk tool this server exposes, in one view.
All high-risk MCP tools → Every high-risk tool across the catalogue, and the policy pattern that contains them.
The MCP Attack Database → Documented attack patterns against MCP deployments — and the policies that stop them.
Agent sandbox → Bounding what an agent can execute and where the boundary should sit.
Least privilege for MCP → Granting agents the minimum tool surface the task needs.
Rate Limiting MCP Tool Calls: A Practical Guide →
MCP Security: Why Prompt Guardrails Aren't Enough →

FAQ

Questions about refresh_index

What does the refresh_index tool do? +

Trigger a re-scan of the Maven repository. This will re-index all artifacts. It is categorised as a Execute tool in the Maven Indexer MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.

How do I enforce a policy on refresh_index? +

Register the Maven Indexer MCP server in PolicyLayer and add a rule for refresh_index: 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 Maven Indexer. Nothing to install.

What risk level is refresh_index? +

refresh_index is a Execute tool with high risk. Execute tools should be rate-limited and have argument validation enabled.

Can I rate-limit refresh_index? +

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

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

refresh_index is provided by the Maven Indexer MCP server (tangcent/maven-indexer-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.

Enforce policy on every Maven Indexer tool call.

Start from Maven Indexer, add the rest of your stack, and see everything your agents can call. Then put policy on all of it.

CHECK YOUR STACK →