---
author: "Umesh Malik"
canonical: "https://umesh-malik.com/blog/tag/agent-design"
description: "Explore articles tagged with Agent Design by Umesh Malik — AI Engineer, LLM & GenAI Developer. Learn Agent Design best practices, practical tips, and in-depth guides."
title: "Umesh Malik's Blog - Agent Design Articles | Agent Design Tutorials"
tokens: 424
generator: "scripts/generate-page-markdown.mjs"
---

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# Agent Design

3 articles

 [![Swapping bespoke search tools for generic grep, glob and view raised Copilot code review cost until the system prompt was rewritten to be diff-anchored](https://umesh-malik.com/blog/cut-agent-tool-call-cost-prompt-rewrite-cover.png)

AI Coding Agents & DX • Aug 14, 2026

### Cut agent tool call cost: GitHub's 20% fix was a prompt rewrite

Agent tool call cost jumped after you gave it better tools? GitHub hit that on Copilot code review and won ~20% back with a prompt rewrite, not new tools.

9 min read

Read more →](https://umesh-malik.com/blog/cut-agent-tool-call-cost-prompt-rewrite)

 [![Agent harness design diagram: a model's reasoning discarded each turn versus reasoning retained and context compacted across turns](https://umesh-malik.com/blog/agent-harness-design-arc-agi-3-cover.png)

AI Engineering • Aug 5, 2026

### Agent Harness Design: Why an ARC-AGI-3 Score Tripled

Agent harness design decided a benchmark: OpenAI's ARC-AGI-3 score went 13.3% → 38.3% with zero model changes. What that means for your agent loop.

11 min read

Read more →](https://umesh-malik.com/blog/agent-harness-design-arc-agi-3)

 [![Agent-to-human delegation — an AI agent handing a task to a human coworker in a chat tool](https://umesh-malik.com/blog/agent-to-human-delegation-cover.png)

AI Engineering • Aug 3, 2026

### Agent-to-Human Delegation: Why Your AI Shouldn't DM Coworkers

Agent-to-human delegation is the pattern nobody designed for: your AI messaging a coworker. Why it lands badly, and the handoff rules that fix it.

10 min read

Read more →](https://umesh-malik.com/blog/agent-to-human-delegation)