share_file · Mail Cal Drive MCP: Risk & Policy

WHAT IT DOES

What share_file does on Mail Cal Drive

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

WHY IT NEEDS A POLICY

Why share_file needs a policy

The tool modifies access control lists and file-sharing settings, which are reversible configuration changes (Write category). Severity is high because unintended sharing could expose sensitive data to unintended recipients or the public; however, it is not Destructive since the shared file itself remains intact and permissions can be revoked.

From the tool's definition share_file: Share a file with a user/group or create a public link. This modifies file access permissions and can generate public sharing links, both of which alter data state.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

share_file Rate-limited

share_file 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": {
    "share_file": {
      "limits": [
        {
          "counter": "share_file_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 Mail Cal Drive, so you can run agents against it safely.

FAQ

Questions about share_file

What does the share_file tool do? +

Share a file with a user/group or create a public link. It is categorised as a Write tool in the Mail Cal Drive MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on share_file? +

Register the Mail Cal Drive MCP server in PolicyLayer and add a rule for share_file: 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 Mail Cal Drive. Nothing to install.

What risk level is share_file? +

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

Can I rate-limit share_file? +

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

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

share_file is provided by the Mail Cal Drive MCP server (rumbitopi/mail-cal-drive-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.