update_index_tool · Astrolabe MCP: Risk & Policy

WHAT IT DOES

What update_index_tool does on Astrolabe

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

WHY IT NEEDS A POLICY

Why update_index_tool needs a policy

The tool name strongly suggests it updates/modifies the search index rather than merely reading it. This is a Write action because it alters the state of the indexing system reversibly (an index can be rebuilt or rolled back). Severity is medium because corrupting the index could impact all documentation retrieval for users, but the effect is not permanent data deletion.

From the tool's definition Tool name 'update_index_tool' indicates modification of an index structure. The server context shows this is a documentation indexing system, so updating the index would modify how documents are catalogued and searchable.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

update_index_tool Rate-limited

update_index_tool 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": {
    "update_index_tool": {
      "limits": [
        {
          "counter": "update_index_tool_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 Astrolabe, so you can run agents against it safely.

FAQ

Questions about update_index_tool

What does the update_index_tool tool do? +

update_index_tool. It is categorised as a Write tool in the Astrolabe MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on update_index_tool? +

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

What risk level is update_index_tool? +

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

Can I rate-limit update_index_tool? +

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

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

update_index_tool is provided by the Astrolabe MCP server (zebrr/astrolabe-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.