PreToolUse

PreToolUse is a hook for Claude Code from trebormc/drupal-ai-agents. Its token cost is not measured, scanned C, original, Apache-2.0.

A pre-tool hook that runs a shell check before the coding agent uses Bash. It can block commands matching listed patterns, including commits, pushes, hard resets, some file deletion, and Docker commands.

In plain words
What is it for?
Use it to enforce restrictions on Bash commands during an agent session. Its exact protections depend on the inline shell rule it contains.
Why use it?
It adds a safeguard before operations that may change project history, delete files, or affect containers. The configured check returns a denial for matching commands.

Hook for Claude Code

One of 2 entries in settings.json — they are configured in one file and arrive together.

Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

agentmods
npx agentmods add hooks/trebormc/drupal-ai-agents/pre-tool-use
Clone the repo
git clone --depth 1 https://github.com/trebormc/drupal-ai-agents

Made for: Claude Code.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

agentmods badge for PreToolUse

README.md
[![agentmods](https://agentmods.dev/badge/hooks/trebormc/drupal-ai-agents/pre-tool-use.svg)](https://agentmods.dev/hooks/trebormc/drupal-ai-agents/pre-tool-use)
Your own site
<a href="https://agentmods.dev/hooks/trebormc/drupal-ai-agents/pre-tool-use"><img src="https://agentmods.dev/badge/hooks/trebormc/drupal-ai-agents/pre-tool-use.svg" alt="Measured on agentmods" height="20"></a>
Per session not measured What this adds to a session before it is invoked.
When invoked not measured Not applicable: nothing here is loaded into a session.
Security scan C 1 finding. Scan, not verified.
Origin original No closer match found in the catalogue.
Security

Grade C, and why

PreToolUse scanned grade C with 1 finding against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 3d ago.

A static scan of the commands this hook runs, not an audit. A hook is shell that executes on your machine at the event it names, which is why every command in it is printed with what was found.

Recursive force deletehighDestructive command

rm -rf with a variable or a broad path is one typo away from removing the wrong tree.

"command": "cmd=$(jq -r '.tool_input.command'); case \"$cmd\" in *'git commit'*|*'git push'*|*'git reset --hard'*|*'git add '*|*'rm -rf '*|*'docker '*) echo '{\"hookSpecificOutput\":{\"hookEventName\":\"PreToolUse\",\"pe
.claude/settings.json · 14 lines

What it actually says

{
  "PreToolUse": [
    {
      "matcher": "Bash",
      "hooks": [
        {
          "type": "command",
          "command": "cmd=$(jq -r '.tool_input.command'); case \"$cmd\" in *'git commit'*|*'git push'*|*'git reset --hard'*|*'git add '*|*'rm -rf '*|*'docker '*) echo '{\"hookSpecificOutput\":{\"hookEventName\":\"PreToolUse\",\"permissionDecision\":\"deny\",\"permissionDecisionReason\":\"Destructive, git write, or docker operations are blocked. Present changes for user review instead.\"}}'; exit 2;; esac",
          "timeout": 5
        }
      ]
    }
  ]
}
Same file

What else settings.json configures

This page is one entry in a file that holds 2. Installing the file brings all of them; each is measured and scanned on its own page.

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 3d ago First seen · 14 lines scan C b5685ab105dc

Subscribe to this mod's changes

PreToolUse is a hook published in the GitHub repository trebormc/drupal-ai-agents (10 stars, last pushed 1mo ago), licensed Apache-2.0. Its token cost is not measured: a hook is shell that never enters the context. A static security scan graded it C with 1 finding (recursive force delete). No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-31.