update_blocks · Mnemosyne MCP: Risk & Policy

WHAT IT DOES

What update_blocks does on Mnemosyne MCP

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

WHY IT NEEDS A POLICY

Why update_blocks needs a policy

The name 'update_blocks' suggests creating or modifying data blocks, which aligns with Write operations (reversible changes). The tool operates within a knowledge graph management system with OAuth authentication. Without a formal description, confidence is moderate (0.75). The tool does not appear to delete data irreversibly (which would be Destructive) or execute arbitrary code (which would be Execute).

From the tool's definition Tool name 'update_blocks' indicates modification of data blocks within a knowledge graph. Server context shows the system manages Mnemosyne knowledge graphs where 'update' operations are reversible modifications.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

update_blocks Rate-limited

update_blocks 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_blocks": {
      "limits": [
        {
          "counter": "update_blocks_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 Mnemosyne MCP, so you can run agents against it safely.

FAQ

Questions about update_blocks

What does the update_blocks tool do? +

update_blocks. It is categorised as a Write tool in the Mnemosyne 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_blocks? +

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

What risk level is update_blocks? +

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

Can I rate-limit update_blocks? +

Yes. Add a rate_limit block to the update_blocks 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_blocks completely? +

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

update_blocks is provided by the Mnemosyne MCP server (sophia-labs/mnemosyne-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.