AI agents call list_teams 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 retrieves and queries team metadata without modifying or deleting any data. It falls squarely into the Read category. Severity is medium rather than low because unauthorized enumeration of all teams a user has access to could enable social engineering, targeted attacks on specific teams, or discovery of sensitive team structures; however, no direct data destruction or financial impact occurs.
From the tool's definition Tool description states 'List all Microsoft Teams' - a retrieval operation with no modification. Returns 'team names, descriptions, and IDs' - read-only data access.
Attacks that exploit this kind of access
List all Microsoft Teams that the current user is a member of. Returns team names, descriptions, and IDs. 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_teams: 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_teams 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_teams 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_teams. 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_teams 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.