This record as markdown: /tools/hybridlabor-api-aos/close-window.md
What close_window does on Aos
AI agents call close_window to permanently remove resources in Aos, typically in cleanup and lifecycle workflows. It does its job in a single call, and there is no undo.
Why close_window is rated Critical
Closing a window cannot be undone; any unsaved data in that window is lost. This maps to Destructive rather than Write because the operation is not reversible. The blast radius is high since an AI agent could inadvertently close critical application windows containing unsaved work.
From the tool's definition 'Close a window' — closing a window is an irreversible action that terminates the window and may discard unsaved state or work within that application.
Attacks that exploit this kind of access
The rule that runs close_window safely
PolicyLayer is an MCP gateway: it sits between your AI agents and Aos, and checks every tool call against a rule you set before the call runs. Nothing changes on the server itself. For close_window, this is the rule to start with:
close_window is removed from the agent's tool list entirely, so the agent never calls it. The rest of the server keeps working.
The button opens the PolicyLayer dashboard: create your workspace, connect Aos, apply this rule, and every close_window call is checked against it from then on.
Questions about close_window
Close a window. It is categorised as a Destructive tool in the Aos MCP Server, which means it can permanently delete or destroy data. Block by default and require explicit approval.
Register the Aos MCP server in PolicyLayer and add a rule for close_window: 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 Aos. Nothing to install.
close_window is a Destructive tool with critical risk. Critical-risk tools should be blocked by default and only enabled with explicit human approval.
Yes. Add a rate_limit block to the close_window 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 close_window. 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.
close_window is provided by the Aos MCP server (@hybridlabor-api/aos). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
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