AI agents call pane_get_metadata to retrieve information from Wmux without modifying anything — typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.
This tool retrieves existing metadata from a pane without modifying, deleting, or executing anything. It is a straightforward read operation with minimal blast radius — worst case an agent learns metadata details about an already-open pane, which poses no destructive or financial risk.
From the tool's definition Tool name 'pane_get_metadata' and description explicitly states 'Read the metadata attached to a leaf pane' — a retrieval operation with no side effects. Returns structured data (paneId, metadata, version) only.
Attacks that exploit this kind of access
Read the metadata attached to a leaf pane in the calling workspace. Returns { paneId, metadata, version }. A version of 0 means no metadata has ever been written for this pane (the. It is categorised as a Read tool in the Wmux MCP Server, which means it retrieves data without modifying state.
Register the Wmux MCP server in PolicyLayer and add a rule for pane_get_metadata: 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 Wmux. Nothing to install.
pane_get_metadata 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 pane_get_metadata 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 pane_get_metadata. 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.
pane_get_metadata is provided by the Wmux MCP server (openwong2kim/wmux). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
pane_get_metadata is one line of Wmux's registry record.
The record carries the whole server: verified identity, auth posture, risk grade, every tool classified, recommended policy — re-checked continuously.
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