update_entities · Elasticsearch Knowledge Graph for MCP

WHAT IT DOES

What update_entities does on Elasticsearch Knowledge Graph for MCP

AI agents use update_entities to create or update resources in Elasticsearch Knowledge Graph for MCP — usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your Elasticsearch Knowledge Graph for MCP environment.

THE RISK

Medium Risk

Why update_entities needs a policy

This tool modifies existing entities within the knowledge graph but does not delete or irreversibly destroy data (that would be delete_entities). Updates are reversible through subsequent edits, making this a Write operation.

From the tool's definition Tool name 'update_entities' and description 'Update entities in knowledge graph (memory)' indicate modification of stored data. The verb 'update' and context of a knowledge graph storing entities confirm reversible data changes.

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

POLICY

How to control update_entities

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

policy.json

{
  "version": "1",
  "default": "deny",
  "tools": {
    "update_entities": {
      "limits": [
        {
          "counter": "update_entities_rate",
          "window": "minute",
          "max": 30,
          "scope": "grant"
        }
      ]
    }
  }
}

update_entities 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.

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

LIMIT THIS TOOL →

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EXPLORE

Related tools and policies

More Elasticsearch Knowledge Graph for MCP tools

Destructive delete_entities Delete multiple entities and their associated relations from the knowledge graph Destructive delete_observations Delete specific observations from entities in the knowledge graph Destructive delete_relations Delete multiple relations from the knowledge graph Destructive delete_zone Delete a memory zone and all its entities/relations. Destructive move_entities Move entities between zones (copy + delete from source). Write add_observations Add new observations to existing entities in the knowledge graph Write copy_entities Copy entities between zones with optional relation handling. Write create_entities Create multiple new entities in the knowledge graph

All 23 Elasticsearch Knowledge Graph for MCP tools →

Write tools on other servers

M-Team MCP Server download_torrent YouTube MCP Server generate_video_title Android Forensics ADB MCP Server combine_reports 0xarchive web3_signup

Go deeper

The MCP Attack Database → Documented attack patterns against MCP deployments — and the policies that stop them.
Argument validation → Checking tool call arguments against schema and policy before they run.
Scoped token → Per-person credentials that grant a defined subset of servers and tools.
Rate Limiting MCP Tool Calls: A Practical Guide →
MCP Security: Why Prompt Guardrails Aren't Enough →

FAQ

Questions about update_entities

What does the update_entities tool do? +

Update entities in knowledge graph (memory). It is categorised as a Write tool in the Elasticsearch Knowledge Graph for MCP 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_entities? +

Register the Elasticsearch Knowledge Graph for MCP server in PolicyLayer and add a rule for update_entities: 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 Elasticsearch Knowledge Graph for MCP. Nothing to install.

What risk level is update_entities? +

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

Can I rate-limit update_entities? +

Yes. Add a rate_limit block to the update_entities 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_entities completely? +

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

update_entities is provided by the Elasticsearch Knowledge Graph for MCP server (j3k0/mcp-brain-tools). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.

Enforce policy on every Elasticsearch Knowledge Graph for MCP tool call.

Start from Elasticsearch Knowledge Graph for MCP, add the rest of your stack, and see everything your agents can call. Then put policy on all of it.

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23 Elasticsearch Knowledge Graph for MCP tools catalogued and risk-classified — across an index of 43,000+ MCP servers.