AI agents call list_channels to retrieve information from Teams without modifying anything — typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.
This tool queries and retrieves metadata about Teams channels without creating, modifying, deleting, or executing any operations. It is a straightforward information retrieval operation with minimal risk even if an AI agent calls it unexpectedly, as it only exposes existing channel metadata that authorized users can already view.
From the tool's definition Tool performs 'List all channels' and 'Returns channel names, descriptions, types, and IDs' — a retrieval operation with no modification, deletion, or execution of side-effects.
Attacks that exploit this kind of access
List all channels in a specific Microsoft Team. Returns channel names, descriptions, types, and IDs for the specified team. It is categorised as a Read tool in the Teams MCP Server, which means it retrieves data without modifying state.
Register the Teams MCP server in PolicyLayer and add a rule for list_channels: 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 Teams. Nothing to install.
list_channels 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_channels 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_channels. 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_channels is provided by the Teams MCP server (@floriscornel/teams-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.