agentmods.dev

PreToolUse

PreToolUse is a hook for Claude Code from Jartan-LLC/grimoire. Its token cost is not measured, scanned A, original, MIT.

A check that runs before the agent uses Bash, the command-line tool for running shell commands. For selected GitHub and Git actions, it tells the agent to follow the project's documented conventions.

In plain words
What is it for?
Use it before Git commits, pushes, tags, and GitHub issue or pull-request creation, editing, commenting, or review commands.
Why use it?
It adds a reminder before actions such as committing, pushing, or creating and editing issues or pull requests. This helps reduce convention mistakes during write operations.

Hook for Claude Code

Written for Claude Code: PreToolUse hook event.

Part of the gitwise plugin — 1 skill, 1 hook shipped together

not rated 2 18d ago A scan tokens not measured original MIT
View the source file Jartan-LLC/grimoire
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/jartan-llc/grimoire/pre-tool-use
Clone the repo
git clone --depth 1 https://github.com/Jartan-LLC/grimoire

Made for: Claude Code.

Or install gitwise, the plugin that ships this one along with the rest of its 1 skill, 1 hook.

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/jartan-llc/grimoire/pre-tool-use.svg)](https://agentmods.dev/hooks/jartan-llc/grimoire/pre-tool-use)
Your own site
<a href="https://agentmods.dev/hooks/jartan-llc/grimoire/pre-tool-use"><img src="https://agentmods.dev/badge/hooks/jartan-llc/grimoire/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 A 0 findings. Scan, not verified.
Origin original No closer match found in the catalogue.
Security

Grade A, and why

PreToolUse scanned grade A with 0 findings 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 5d 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.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

plugins/gitwise/hooks/hooks.json · 15 lines

What it actually says

{
  "PreToolUse": [
    {
      "matcher": "Bash",
      "hooks": [
        {
          "type": "command",
          "command": "node -e \"let d='';process.stdin.on('data',c=>d+=c);process.stdin.on('end',()=>{try{const i=JSON.parse(d);const cmd=i.tool_input?.command||'';if(/\\bgh\\s+(pr|issue)\\s+(create|comment|edit)|\\bgh\\s+pr\\s+review\\b|\\bgit\\s+(commit|push|tag)\\b/.test(cmd)){console.log(JSON.stringify({hookSpecificOutput:{hookEventName:'PreToolUse',additionalContext:'Load the github-conventions skill. Use 1./2./3. for numbered lists, never #1/#2/#3. Follow conventional commits for commit messages.'}}));}else{console.log(d)}}catch{console.log(d)}})\"",
          "statusMessage": "Checking GitHub conventions..."
        }
      ],
      "description": "Load github-conventions for write operations (pr/issue create/comment, git commit/push)"
    }
  ]
}
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. 5d ago First seen · 15 lines scan A cc5e66790ad3

Subscribe to this mod's changes

PreToolUse is a hook published in the GitHub repository Jartan-LLC/grimoire (2 stars, last pushed 18d ago), licensed MIT. Its token cost is not measured: a hook is shell that never enters the context. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-31.

Git and workflowSecurityai-agentsclaudeclaude-codeclaude-skillscodexcodex-skill
Related

Other hooks, from other repositories

Stop

Runs when the agent finishes a response, running an inline shell check. From tody-agent/codymaster.

tody-agent/codymaster · not measured

PostToolUse

Runs after a tool call finishes for Write and Edit tool calls, executing format_and_lint.sh. From supabase/supabase.

supabase/supabase · not measured

SessionStart

Runs when a session starts on startup, executing install_pkgs.sh. From supabase/supabase.

supabase/supabase · not measured

SessionStart

Runs when a session starts, executing on-start.js via node. From google-gemini/gemini-cli.

google-gemini/gemini-cli · not measured

PreToolUse

Runs before the agent uses a tool for Bash tool calls, running an inline shell check. From apache/superset.

apache/superset · not measured

PreToolUse

Runs before the agent uses a tool, executing pre-write.sh and pre-bash.sh (2 commands). From anthropics/claude-cookbooks.

anthropics/claude-cookbooks · not measured