shellcheck

Runs ShellCheck (shell script linter) and returns structured diagnostics (file, line, column, rule, severity, message).

SERVERNpm SOURCEDave-London/Pare

High RISK CLASS

Category Execute

Parameters 00 required

Recommended Rate-limitedsee the rule below

Registry record Grade F, identity unverified Pull the record →

This record as markdown: /tools/io-github-dave-london-npm/shellcheck.md

WHAT IT DOES

What shellcheck does on Npm

AI agents invoke shellcheck to trigger actions in Npm. What it does depends on the arguments the agent supplies, and its effects often reach beyond the immediate call: builds kicked off, notifications sent, workflows started.

RISK

Why shellcheck is rated High

The tool executes an external process (ShellCheck) against shell script files. While it is read-only in intent (linting/analysis), it actively runs an external tool/command on files, which classifies it as Execute. Misuse could be leveraged to scan arbitrary files on the filesystem. Severity is medium due to the read-only nature of the analysis but the ability to target arbitrary files.

From the tool's definition Runs ShellCheck (shell script linter) and returns structured diagnostics

Attacks that exploit this kind of access

RECOMMENDED RULE

The rule that runs shellcheck safely

PolicyLayer is an MCP gateway: it sits between your AI agents and Npm, and checks every tool call against a rule you set before the call runs. Nothing changes on the server itself. For shellcheck, this is the rule to start with:

shellcheck Rate-limited

shellcheck stays usable, but rate-capped: a runaway agent can't fire it dozens of times a minute. Everything else on the server is denied unless you say otherwise.

View as policy code

policy.json

{
  "version": "1",
  "default": "deny",
  "tools": {
    "shellcheck": {
      "limits": [
        {
          "counter": "shellcheck_rate",
          "window": "minute",
          "max": 10,
          "scope": "grant"
        }
      ]
    }
  }
}

RATE-LIMIT THIS TOOL → Instant setup, no code required.

The button opens the PolicyLayer dashboard: create your workspace, connect Npm, apply this rule, and every shellcheck call is checked against it from then on.

FAQ

Questions about shellcheck

What does the shellcheck tool do? +

Runs ShellCheck (shell script linter) and returns structured diagnostics (file, line, column, rule, severity, message). It is categorised as a Execute tool in the Npm MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.

How do I enforce a policy on shellcheck? +

Register the Npm MCP server in PolicyLayer and add a rule for shellcheck: 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 Npm. Nothing to install.

What risk level is shellcheck? +

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

Can I rate-limit shellcheck? +

Yes. Add a rate_limit block to the shellcheck 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.

How do I block shellcheck completely? +

Set action: deny in the PolicyLayer policy for shellcheck. 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 shellcheck? +

shellcheck is provided by the Npm MCP server (Dave-London/Pare). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.

KEEP EXPLORING

More on Npm, and thousands of servers like it.

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Guides

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