High Risk →

shell_command

Run a shell command on the system

Executes arbitrary system commands

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

impact-preview Execute Risk 5/5

AI agents invoke shell_command to trigger processes or run actions in Impact Preview. Execute operations can have side effects beyond the immediate call -- triggering builds, sending notifications, or starting workflows. Rate limits and argument validation are essential to prevent runaway execution.

shell_command can trigger processes with real-world consequences. An uncontrolled agent might start dozens of builds, send mass notifications, or kick off expensive compute jobs. Intercept enforces rate limits and validates arguments to keep execution within safe bounds.

Execute tools trigger processes. Rate-limit and validate arguments to prevent unintended side effects.

io-github-agent-polis-impact-preview.yaml
tools:
  shell_command:
    rules:
      - action: allow
        rate_limit:
          max: 10
          window: 60
        validate:
          required_args: true

See the full Impact Preview policy for all 9 tools.

Tool Name shell_command
Category Execute
Risk Level High

View all 9 tools →

Agents calling execute-class tools like shell_command 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 Execute risk category across the catalogue. The same policy patterns (rate-limit, validate) apply to each.

shell_command is one of the high-risk operations in Impact Preview. For the full severity-focused view — only the high-risk tools with their recommended policies — see the breakdown for this server, or browse all high-risk tools across every MCP server.

What does the shell_command tool do? +

Run a shell command on the system. It is categorised as a Execute tool in the Impact Preview MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.

How do I enforce a policy on shell_command? +

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

What risk level is shell_command? +

shell_command is a Execute tool with high risk. Execute tools should be rate-limited and have argument validation enabled.

Can I rate-limit shell_command? +

Yes. Add a rate_limit block to the shell_command 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 shell_command completely? +

Set action: deny in the Intercept policy for shell_command. 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 shell_command? +

shell_command is provided by the Impact Preview MCP server (impact-preview). Intercept sits as a proxy in front of this server to enforce policies before tool calls reach the server.

Enforce policies on Impact Preview

Open source. One binary. Zero dependencies.

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

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