write_create_dataset_item · Langfuse MCP Server MCP

WHAT IT DOES

What write_create_dataset_item does on Langfuse MCP Server

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

WHY IT NEEDS A POLICY

Why write_create_dataset_item needs a policy

This tool creates new dataset items in Langfuse, which is a reversible write operation. It modifies project data but does not delete, destroy, or move money. The 'write operation will modify your Langfuse project' language confirms it is Write category.

From the tool's definition Tool name includes 'create' and description states 'Add an item to a dataset' and 'will modify your Langfuse project', indicating reversible data creation/modification without deletion or financial impact.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

write_create_dataset_item Rate-limited

write_create_dataset_item 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": {
    "write_create_dataset_item": {
      "limits": [
        {
          "counter": "write_create_dataset_item_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 Langfuse MCP Server, so you can run agents against it safely.

FAQ

Questions about write_create_dataset_item

What does the write_create_dataset_item tool do? +

Add an item to a dataset with input/output examples. This write operation will modify your Langfuse project. It is categorised as a Write tool in the Langfuse MCP Server MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on write_create_dataset_item? +

Register the Langfuse MCP Server MCP server in PolicyLayer and add a rule for write_create_dataset_item: 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 Langfuse MCP Server. Nothing to install.

What risk level is write_create_dataset_item? +

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

Can I rate-limit write_create_dataset_item? +

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

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

write_create_dataset_item is provided by the Langfuse MCP Server MCP server (therealsachin/langfuse-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.