Automatic actions that run before the agent uses Bash, Edit, Write, or apply_patch tools. They check whether a listed standard operating procedure applies and run agent-hook scripts.

They are for checking procedures and running configured pre-tool hooks before shell commands or edits.

They provide a checkpoint before commands or file changes, helping the agent follow relevant instructions first.

PreToolUse — Hook by SSBun

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/ssbun/csl-agent-kit/pre-tool-use

Clone the repo

git clone --depth 1 https://github.com/SSBun/csl-agent-kit

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 2d 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.

hooks/hooks.json · 25 lines

What it actually says

{
  "PreToolUse": [
    {
      "matcher": "Bash|Edit|Write|apply_patch",
      "hooks": [
        {
          "type": "command",
          "command": "printf '%s\\n' 'If a listed SOP matches this task by when_to_use or name, read the full SOP before this tool call and verify its completion criteria before final.'",
          "timeout": 5,
          "statusMessage": "Checking SOP reminder"
        }
      ]
    },
    {
      "hooks": [
        {
          "type": "command",
          "command": "sh -c 'root=\"${PLUGIN_ROOT:-${CLAUDE_PLUGIN_ROOT:-}}\"; exec node \"$root/skills/meta/agent-hooks/scripts/agent-hooks.js\" dispatch'",
          "timeout": 65,
          "statusMessage": "Running Agent Hooks before-tool triggers"
        }
      ]
    }
  ]
}

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.

2d ago First seen · 25 lines scan A 88e8c9beccba

Subscribe to this mod's changes

PreToolUse is a hook published in the GitHub repository SSBun/csl-agent-kit (10 stars, last pushed 4d 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.

PreToolUse

Getting it into your agent

Grade A, and why

Nothing flagged

What it actually says

What this file has done since we first saw it

Other hooks, from other repositories

PostToolUse

SessionStart

SessionStart

PreToolUse

PreToolUse

SessionStart