hash_mset · Redis MCP: Risk & Policy

WHAT IT DOES

What hash_mset does on Redis MCP

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

WHY IT NEEDS A POLICY

Why hash_mset needs a policy

This tool creates or updates hash field values in Redis, which is reversible data modification. It does not delete data (which would be Destructive), execute arbitrary code (Execute), or move money (Financial). The severity is medium because bulk write operations can impact data integrity if misused, but the blast radius is limited to hash field modifications within a single Redis instance.

From the tool's definition hash_mset performs batch setting of hash fields in Redis, which creates or modifies data. The tool name 'mset' (multiple set) and description '批量设置哈希字段' (batch set hash fields) confirm this is a write operation that modifies Redis hash data structures.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

hash_mset Rate-limited

hash_mset 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": {
    "hash_mset": {
      "limits": [
        {
          "counter": "hash_mset_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 Redis MCP, so you can run agents against it safely.

FAQ

Questions about hash_mset

What does the hash_mset tool do? +

批量设置哈希字段. It is categorised as a Write tool in the Redis 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 hash_mset? +

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

What risk level is hash_mset? +

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

Can I rate-limit hash_mset? +

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

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

hash_mset is provided by the Redis MCP server (pickstar-2002/redis-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.