Low Risk

list_clusters

list_clusters

How to control list_clusters ↓

What list_clusters does on Amazon Bedrock Knowledge Base Retrieval MCP Server

AI agents call list_clusters to retrieve information from Amazon Bedrock Knowledge Base Retrieval MCP Server without modifying anything — typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.

Low Risk

Why list_clusters needs a policy

The naming convention 'list_*' strongly suggests a retrieval operation that queries existing cluster information without side effects. This is a standard Read category action. The lack of a description reduces confidence slightly, but the tool name alone provides sufficient evidence of its read-only nature.

From the tool's definition Tool name 'list_clusters' indicates listing/querying operation with no modification capability. The empty description provides no contradictory evidence of destructive or write operations.

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

How to control list_clusters

PolicyLayer is an MCP gateway — it sits between your AI agents and Amazon Bedrock Knowledge Base Retrieval MCP Server, and nothing reaches the server without passing your rules. This is the rule we recommend for list_clusters:

policy.json
{
  "version": "1",
  "default": "deny",
  "tools": {
    "list_clusters": {}
  }
}

list_clusters is read-only, so it stays allowed — but everything else on the server is denied unless you say otherwise.

  1. Create a free account and register Amazon Bedrock Knowledge Base Retrieval MCP Server — nothing to install.
  2. Add this policy — paste it, or build it visually.
  3. Point your MCP client (Claude, Cursor, anything) at your gateway URL.
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Related tools and policies

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Questions about list_clusters

What does the list_clusters tool do? +

list_clusters. It is categorised as a Read tool in the Amazon Bedrock Knowledge Base Retrieval MCP Server MCP Server, which means it retrieves data without modifying state.

How do I enforce a policy on list_clusters? +

Register the Amazon Bedrock Knowledge Base Retrieval MCP Server MCP server in PolicyLayer and add a rule for list_clusters: 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 Amazon Bedrock Knowledge Base Retrieval MCP Server. Nothing to install.

What risk level is list_clusters? +

list_clusters is a Read tool with low risk. Read-only tools are generally safe to allow by default.

Can I rate-limit list_clusters? +

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

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

list_clusters is provided by the Amazon Bedrock Knowledge Base Retrieval MCP Server MCP server (awslabs.bedrock-kb-retrieval-mcp-server). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.

Enforce policy on every Amazon Bedrock Knowledge Base Retrieval MCP Server tool call.

Start from Amazon Bedrock Knowledge Base Retrieval MCP Server, add the rest of your stack, and see everything your agents can call. Then put policy on all of it.

Free to start. No card required.

805 Amazon Bedrock Knowledge Base Retrieval MCP Server tools catalogued and risk-classified — across an index of 43,000+ MCP servers.

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