Check if a phone number or email is registered for iMessage.
AI agents call check_imessage to retrieve information from Bluebubbles without modifying anything — typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.
This tool queries the iMessage system to verify registration status of contact identifiers. It retrieves data (boolean result or registration status) without creating, modifying, deleting, or executing operations. The blast radius is minimal as it only exposes whether a contact uses iMessage, which is low-sensitivity metadata.
From the tool's definition Tool name 'check_imessage' and description 'Check if a phone number or email is registered for iMessage' indicate a read-only query operation that retrieves information without modification or side effects.
Attacks that exploit this kind of access
Check if a phone number or email is registered for iMessage. It is categorised as a Read tool in the Bluebubbles MCP Server, which means it retrieves data without modifying state.
Register the Bluebubbles MCP server in PolicyLayer and add a rule for check_imessage: 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 Bluebubbles. Nothing to install.
check_imessage is a Read tool with low risk. Read-only tools are generally safe to allow by default.
Yes. Add a rate_limit block to the check_imessage 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.
Set action: deny in the PolicyLayer policy for check_imessage. 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.
check_imessage is provided by the Bluebubbles MCP server (metaember/bluebubbles-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Every MCP server has a record like this.
Type a name, get the same breakdown: verified identity, auth posture, risk grade, capabilities, recommended policy.
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