index_refresh · Frontmatter MCP: Risk & Policy

WHAT IT DOES

What index_refresh does on Frontmatter MCP

AI agents invoke index_refresh to trigger actions in Frontmatter MCP. What it does depends on the arguments the agent supplies, and its effects often reach beyond the immediate call — builds kicked off, notifications sent, workflows started.

WHY IT NEEDS A POLICY

Why index_refresh needs a policy

The tool name 'index_refresh' suggests it triggers a re-indexing operation on the document store or DuckDB index. In the context of this server (which indexes Markdown frontmatter and supports semantic search), refreshing an index is an active operation that re-processes or rebuilds data structures — more than a simple read, but likely reversible. With no description available, confidence is reduced.

From the tool's definition Tool name: index_refresh; description is empty and uninformative.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

index_refresh Rate-limited

index_refresh 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.

View as policy code

policy.json

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

RATE-LIMIT THIS TOOL →

Instant setup, no code required.

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

FAQ

Questions about index_refresh

What does the index_refresh tool do? +

index_refresh. It is categorised as a Execute tool in the Frontmatter MCP MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.

How do I enforce a policy on index_refresh? +

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

What risk level is index_refresh? +

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

Can I rate-limit index_refresh? +

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

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

index_refresh is provided by the Frontmatter MCP server (kzmshx/frontmatter-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.