AI agents call channel_list 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 information about channels in a workspace—a read-only query with no side effects. The explicit note that it does 'NOT' return message history further confirms it is a safe listing operation. No data is created, modified, deleted, or executed. The blast radius of misuse is minimal—an agent could learn about workspace structure but cannot cause harm.
From the tool's definition Tool performs a list operation that returns channel metadata (id, name, visibility, topic, status, members) without modifying data or accessing sensitive content like message history.
Attacks that exploit this kind of access
List all channels visible to the calling workspace. Returns the channel metadata (id, name, visibility, topic, status, members) but NOT the message history — use a follow-up get for history. 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 channel_list: 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.
channel_list 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 channel_list 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 channel_list. 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.
channel_list 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.
channel_list 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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