A set of hooks that run before an agent uses skills, starts another task, writes or edits files, or performs related tool actions. They run PowerShell checks for skills, tasks, memory, coding libraries, routing, and plugin reminders.

Use it to enforce pre-action checks, inspect memory, prepare skill and task execution, route models, and record agent or tool activity.

It adds automatic checks and preparation before potentially important agent actions begin.

PreToolUse — Hook by DNYoussef

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/dnyoussef/context-cascade/pre-tool-use

Clone the repo

git clone --depth 1 https://github.com/DNYoussef/context-cascade

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.

Origin

Copies of this mod

1 near-identical copy found in the catalogue:

PostToolUse — 88% identical, 57 lines differ

hooks/hooks.json · 71 lines

How it starts

The opening of the file, as written. The whole thing — 71 lines — stays where its author put it; the contents beside it link to each section on GitHub.

{
  "PreToolUse": [
    {
      "matcher": "Skill",
      "hooks": [
        {
          "type": "command",
          "command": "powershell -ExecutionPolicy Bypass -File \"${CLAUDE_PLUGIN_ROOT}/hooks/enforcement/pre-skill-invoke.ps1\"",
          "timeout": 15000
        },
        {
          "type": "command",
          "command": "powershell -ExecutionPolicy Bypass -File \"${CLAUDE_PLUGIN_ROOT}/hooks/check-skill-mcps.ps1\"",
          "timeout": 30000
        },
        {
          "type": "command",
          "command": "powershell -ExecutionPolicy Bypass -File \"${CLAUDE_PLUGIN_ROOT}/hooks/skill-started.ps1\"",
          "timeout": 10000
        }
      ]
    },
    {
      "matcher": "Task",
      "hooks": [
        {
          "type": "command",
          "command": "powershell -ExecutionPolicy Bypass -File \"${CLAUDE_PLUGIN_ROOT}/hooks/enforcement/pre-task-spawn.ps1\"",
          "timeout": 15000
        },
        {
          "type": "command",
          "command": "powershell -ExecutionPolicy Bypass -File \"${CLAUDE_PLUGIN_ROOT}/hooks/memory-mcp/pre-task-memory-check.ps1\"",
          "timeout": 120000,
          "$comment": "2 minutes for deep triple-tier memory queries"
        },
        {
          "type": "command",
          "command": "powershell -ExecutionPolicy Bypass -File \"${CLAUDE_PLUGIN_ROOT}/hooks/pre-task-plugin-reminder.ps1\"",
          "timeout": 10000
        },
        {
          "type": "command",
          "command": "powershell -ExecutionPolicy Bypass -File \"${CLAUDE_PLUGIN_ROOT}/hooks/guards/pre-coding-library-check.ps1\"",
          "timeout": 60000,
          "$comment": "1 minute for full D:\\Projects scan"
        },
        {
          "type": "command",
          "command": "powershell -ExecutionPolicy Bypass -File \"${CLAUDE_PLUGIN_ROOT}/hooks/multi-model/model-router-pretool.ps1\"",
          "timeout": 15000
        },
        {
          "type": "command",
          "command": "powershell -ExecutionPolicy Bypass -File

Read the full file on GitHub · 71 lines

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 · 71 lines scan A e27ca4c935e6

Subscribe to this mod's changes

PreToolUse is a hook published in the GitHub repository DNYoussef/context-cascade (32 stars, last pushed 1mo 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 2026-08-30.

Data and AI Memory and context Planning

PreToolUse

Getting it into your agent

Grade A, and why

Nothing flagged

Copies of this mod

How it starts

What this file has done since we first saw it

Other hooks, from other repositories

PostToolUse

SessionStart

SessionStart

PreToolUse

PreToolUse

SessionStart