personal_contacts · Personal Brain MCP: Risk & Policy

WHAT IT DOES

What personal_contacts does on Personal Brain

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

WHY IT NEEDS A POLICY

Why personal_contacts needs a policy

The tool performs Read operations (search/view) and Write operations (add/update) on personal contact information. Per the classification rules, Write is the appropriate category since the tool can create or modify contact records reversibly.

From the tool's definition Tool description explicitly lists capabilities: 'Search/view/add/update personal contacts'. The add/update operations are reversible write actions on personal contact data.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

personal_contacts Rate-limited

personal_contacts 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": {
    "personal_contacts": {
      "limits": [
        {
          "counter": "personal_contacts_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 Personal Brain, so you can run agents against it safely.

FAQ

Questions about personal_contacts

What does the personal_contacts tool do? +

Search/view/add/update personal contacts (friends, neighbors, extended family). Returns relationship notes and last interaction date. It is categorised as a Write tool in the Personal Brain MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on personal_contacts? +

Register the Personal Brain MCP server in PolicyLayer and add a rule for personal_contacts: 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 Personal Brain. Nothing to install.

What risk level is personal_contacts? +

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

Can I rate-limit personal_contacts? +

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

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

personal_contacts is provided by the Personal Brain MCP server (phantomts/personal-brain-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.