AI agents call list_sessions to retrieve information from Selenium without modifying anything — typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.
This tool retrieves information about active browser sessions with no side effects. It does not create, modify, delete, or execute anything—it only queries and returns session state. While on a browser automation server alongside more dangerous tools like click, execute_js, and close_session, this particular tool is purely informational.
From the tool's definition Tool name 'list_sessions' and description 'List all active browser sessions' indicate a query operation that retrieves session data without modifying or executing anything. The verb 'list' is explicitly a read operation.
Attacks that exploit this kind of access
List all active browser sessions. It is categorised as a Read tool in the Selenium MCP Server, which means it retrieves data without modifying state.
Register the Selenium MCP server in PolicyLayer and add a rule for list_sessions: 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 Selenium. Nothing to install.
list_sessions 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 list_sessions 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 list_sessions. 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.
list_sessions is provided by the Selenium MCP server (scv-consultants/selenium-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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