Opus failed at a seemingly easy task when I started using Claude Code end of last year.

“Write the content for all the 18 grammar topics.”

It went into plan mode, came up with a plan to write the content topic by topic, and followed the plan.

After it reported all 18 done, I checked. Only 4 were actually written. The other 14 were completed as “coming soon” placeholders. I ended up prompting it lesson by lesson after that.

Back then I didn’t know why, until Anthropic published an article on harness design for long-running application development in March 2026, which named it: context anxiety. Some models begin wrapping up work prematurely as they approach what they believe is their context limit.

Once you know context limit is the root cause, the fix is easy: fan out big tasks with subagents.

I later used fan out plus subagents to complete the content for 250+ grammar topics for the final version of my Grammar Parrot app.

“Use one subagent per grammar topic with /write-lesson skill to write the content for all 250 topics.”

Why does this work? A subagent is a separate session that Claude Code spins out with a fresh context window. So each subagent gets a fresh window to work through the content of one topic, instead of one window trying to survive 250 of them.

I’ve used this pattern for many other tasks since then. For example:

“Come up with 5 design directions, use one subagent per design to write DESIGN.md and mock.html, and save in designs/[slug].”

If Claude Code reports a big task done, check the actual output before you trust the report. And if you’re about to hand it a task with more than a handful of parts, don’t ask one session to do all of them. Give it one subagent per part instead.

#AI #ClaudeCode #VibeCoding #AIAgents #BuildInPublic

This is one of the workflow patterns I share in my Advanced Claude Code workshop. If you are interested in a deep dive into context engineering, building skills, and workflow patterns, my next Advanced Claude Code workshop is on 24 Jul, 10am to 6pm.

Details: https://lnkd.in/eR6WPQnC

If you are new to Claude Code and Terminal, check out my Foundations of Claude Code workshop. It is designed for business professionals with no prior knowledge.

Details: https://lnkd.in/e9r8kScw