hash_bcrypt · Devutils MCP: Risk & Policy

WHAT IT DOES

What hash_bcrypt does on Devutils

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

WHY IT NEEDS A POLICY

Why hash_bcrypt needs a policy

The tool produces a hashed output without modifying any persistent state or stored data directly. While bcrypt is commonly used for password hashing in secure contexts, this tool itself simply transforms input to output (a one-way function). It is categorized as Write rather than Execute because it is a deterministic cryptographic operation, not a code execution or external command invocation.

From the tool's definition Tool name 'hash_bcrypt' and description 'Generate a bcrypt hash of the given input string. Useful for password hashing' indicates the tool creates/generates cryptographic output.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

hash_bcrypt Rate-limited

hash_bcrypt 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_bcrypt": {
      "limits": [
        {
          "counter": "hash_bcrypt_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 Devutils, so you can run agents against it safely.

FAQ

Questions about hash_bcrypt

What does the hash_bcrypt tool do? +

Generate a bcrypt hash of the given input string. Useful for password hashing. It is categorised as a Write tool in the Devutils 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_bcrypt? +

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

What risk level is hash_bcrypt? +

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

Can I rate-limit hash_bcrypt? +

Yes. Add a rate_limit block to the hash_bcrypt 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_bcrypt completely? +

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

hash_bcrypt is provided by the Devutils MCP server (paladini/devutils-mcp-server). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.