Substring search across recent mail. Falls back to Gmail full-text search.
AI agents call find_emails_about to retrieve information from Nexus Core without modifying anything — typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.
This tool retrieves or searches email data without creating, modifying, or deleting messages. It performs a read-only operation (search/query) across the user's mailbox, similar to a standard email search function. No side effects or irreversible actions are possible. Severity is low because the blast radius of misuse is limited to information disclosure of the user's own emails.
From the tool's definition Tool name 'find_emails_about' and description 'Substring search across recent mail' indicate a query-only operation with no data modification, deletion, or external execution.
Attacks that exploit this kind of access
Substring search across recent mail. Falls back to Gmail full-text search. It is categorised as a Read tool in the Nexus Core MCP Server, which means it retrieves data without modifying state.
Register the Nexus Core MCP server in PolicyLayer and add a rule for find_emails_about: 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 Nexus Core. Nothing to install.
find_emails_about 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 find_emails_about 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 find_emails_about. 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.
find_emails_about is provided by the Nexus Core MCP server (noumenon-ai/nexus-core). 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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