Retrieve message history from a specific channel
AI agents call get_channel_history to retrieve information from Slack MCP Server without modifying anything — typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.
This tool performs a retrieval operation on Slack channel data with no side effects. It queries existing data without creating, modifying, deleting, or executing external operations. The read-only nature of the server and the clear retrieval semantics place this firmly in the Read category.
From the tool's definition Tool description states 'Retrieve message history from a specific channel'. Server description explicitly states this is a 'read-only MCP server'. The tool name and description indicate data retrieval with no modification or deletion.
Attacks that exploit this kind of access
Retrieve message history from a specific channel. It is categorised as a Read tool in the Slack MCP Server MCP Server, which means it retrieves data without modifying state.
Register the Slack MCP Server MCP server in PolicyLayer and add a rule for get_channel_history: 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 Slack MCP Server. Nothing to install.
get_channel_history 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 get_channel_history 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 get_channel_history. 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.
get_channel_history is provided by the Slack MCP Server MCP server (mynghn/slack-mcp-server). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Every MCP server has a record like this.
Type a name, get the same breakdown: verified identity, auth posture, risk grade, capabilities, recommended policy.
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