Download hosted content (such as images) from a Teams channel message. Returns the content as base64 encoded data along with metadata. Use this to retrieve images or other inline content embedded in messages.
AI agents call download_message_hosted_content 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 fetches message-hosted content (images, inline media) from Teams messages without modifying, deleting, or executing anything. It is a read-only operation that accesses existing data. Severity is low because downloading chat/channel content, while potentially exposing information, does not have broad destructive or system-wide impact if misused by an agent.
From the tool's definition Tool description states 'Download hosted content' and 'retrieve images or other inline content embedded in messages.' The verb 'download' and 'retrieve' indicate data retrieval.
Attacks that exploit this kind of access
Download hosted content (such as images) from a Teams channel message. Returns the content as base64 encoded data along with metadata. Use this to retrieve images or other inline content embedded in messages. 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 download_message_hosted_content: 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.
download_message_hosted_content 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 download_message_hosted_content 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 download_message_hosted_content. 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.
download_message_hosted_content 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.