Remove What No Longer Matters

Wed, 23 Sep 2026 05:00:10 +0100

Nine chapters have observed, classified, measured, ordered, priced, and architected around context without once deleting anything. That restraint ends here, and it should end nervously. A team ships an automatic cleanup pass over its coding agent’s history: exact-duplicate tool outputs go, failed calls older than four turns go, anything the model flags as done goes. Token counts fall by a third. Two weeks later a migration guardrail the team believed was load-bearing starts failing silently. The deleted material contained the only record of a constraint the project file never stated, a decision reached mid-session and never written anywhere else. Nobody summarised it away. Nobody rewrote it. It was simply removed, by a rule that could not tell a redundant copy from a unique original.

Tools Produce Context

Wed, 23 Sep 2026 05:00:17 +0100

An agent starts a routine task with fifteen integrations connected: file tools, shell, search, web, database, issue tracker, chat, calendar, drive, deployment, monitoring. Before it reads a single project file, tens of thousands of tokens of capability descriptions have already entered its context — names, descriptions, schemas for operations it will never call. Then it runs one search, and 40,000 tokens of matches flood the window for a question answerable from twelve lines. The task fails twice before it begins: once at the price of knowing what it could do, once at the price of seeing what it did. Both prices were design choices. This chapter prices them.

Tool Output on Programmer.ie: Modern AI programming

Remove What No Longer Matters

Tools Produce Context