Low Risk

slack_list_users

List all users in the workspace with pagination support

Bulk/mass operation — affects multiple targets

Part of the Slack MCP MCP server. Enforce policies on this tool with Intercept, the open-source MCP proxy.

jtalk22/slack-mcp-server Read Risk 2/5

AI agents call slack_list_users to retrieve information from Slack MCP without modifying any data. This is common in research, monitoring, and reporting workflows where the agent needs context before taking action. Because read operations don't change state, they are generally safe to allow without restrictions -- but you may still want rate limits to control API costs.

Even though slack_list_users only reads data, uncontrolled read access can leak sensitive information or rack up API costs. An agent caught in a retry loop could make thousands of calls per minute. A rate limit gives you a safety net without blocking legitimate use.

Read-only tools are safe to allow by default. No rate limit needed unless you want to control costs.

jtalk22-slack-mcp-server.yaml
tools:
  slack_list_users:
    rules:
      - action: allow

See the full Slack MCP policy for all 10 tools.

Tool Name slack_list_users
Category Read
Risk Level Low

View all 10 tools →

Agents calling read-class tools like slack_list_users have been implicated in these attack patterns. Read the full case and prevention policy for each:

Browse the full MCP Attack Database →

Other tools in the Read risk category across the catalogue. The same policy patterns (rate-limit, allow) apply to each.

What does the slack_list_users tool do? +

List all users in the workspace with pagination support. It is categorised as a Read tool in the Slack MCP MCP Server, which means it retrieves data without modifying state.

How do I enforce a policy on slack_list_users? +

Add a rule in your Intercept YAML policy under the tools section for slack_list_users. You can allow, deny, rate-limit, or validate arguments. Then run Intercept as a proxy in front of the Slack MCP MCP server.

What risk level is slack_list_users? +

slack_list_users is a Read tool with low risk. Read-only tools are generally safe to allow by default.

Can I rate-limit slack_list_users? +

Yes. Add a rate_limit block to the slack_list_users rule in your Intercept 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.

How do I block slack_list_users completely? +

Set action: deny in the Intercept policy for slack_list_users. 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.

What MCP server provides slack_list_users? +

slack_list_users is provided by the Slack MCP MCP server (jtalk22/slack-mcp-server). Intercept sits as a proxy in front of this server to enforce policies before tool calls reach the server.

Enforce policies on Slack MCP

Open source. One binary. Zero dependencies.

npx -y @policylayer/intercept
github.com/policylayer/intercept →
// GET IN TOUCH

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