---
author: "Umesh Malik"
canonical: "https://umesh-malik.com/blog/tag/agent-harness"
description: "Explore articles tagged with Agent Harness by Umesh Malik — AI Engineer, LLM & GenAI Developer. Learn Agent Harness best practices, practical tips, and in-depth guides."
title: "Umesh Malik's Blog - Agent Harness Articles | Agent Harness Tutorials"
tokens: 288
generator: "scripts/generate-page-markdown.mjs"
---

[← Back to Blog](https://umesh-malik.com/blog)

# Agent Harness

2 articles

 [![The five sandbox tools a Gemini agent hook intercepts, against the two tool families it never sees](https://umesh-malik.com/blog/gemini-agent-hooks-fail-open-cover.png)

AI Security • Aug 19, 2026

### Gemini agent hooks fail open: how to block a tool call anyway

Gemini agent hooks fail open on every error path, and never fire for MCP or function tools. The deny contract, the coverage gap, and what to gate instead.

9 min read

Read more →](https://umesh-malik.com/blog/gemini-agent-hooks-fail-open)

 [![Diagram contrasting a sequential agent loop of ten model round trips with a two-level dependency graph running nine tool calls concurrently](https://umesh-malik.com/blog/parallel-agent-tool-calls-dag-harness-cover.png)

AI Engineering • Aug 6, 2026

### Run agent tool calls in parallel: 10 turns become 2 DAG levels

Run agent tool calls in parallel by swapping the loop for a DAG planner: ten round trips become two levels, plus the cap, budget and critic on top.

10 min read

Read more →](https://umesh-malik.com/blog/parallel-agent-tool-calls-dag-harness)