# Prompt-induced waste in coding agents | PointFive

Canonical: https://www.pointfive.co/blog/prompt-induced-waste-in-coding-agents

Prompt wording, reasoning effort, and the agent harness can change the cost of completing the same task.

By: PointFive Labs

Published: 2026-10-06

[All articles](https://www.pointfive.co/blog) 

PointFive Labs  October 6, 2026

## What changes the cost of a coding task

A coding agent's cost depends on more than the model's token price. Prompt wording, reasoning effort, and the harness that manages tools and context shape how the agent approaches the task.

## What the research found

Controlled experiments found that wording could change reasoning and verification behavior without changing the underlying task. Extra effort helped some difficult tasks but also added cost without improving outcomes. An intervention's value could change with the harness.

These factors need to be evaluated together. Token and cache counts describe the agent's activity; they do not establish that the work became cheaper or more successful.

## Read the paper and inspect the data

This PointFive Labs paper is by Sarel Weinberger and Amir Hozez. Read the versioned paper below and explore the [benchmark and data](https://www.pointfive.co/blog/token-reduction-is-not-cost-reduction#benchmark-and-data) .

Read the version 6 paper on this page

Source: [arXiv, version 6](https://arxiv.org/abs/2608.01347v6) . [Open the PDF](https://arxiv.org/pdf/2608.01347v6) .

[Version 6 on arXiv](https://arxiv.org/abs/2608.01347v6)  | [PointFive Labs](https://www.pointfive.co/labs)

## Related reading

[All articles](https://www.pointfive.co/blog)

- ### [Token reduction is not cost reduction](https://www.pointfive.co/blog/token-reduction-is-not-cost-reduction)

August 6, 2026 3 min read

- ### [Introducing PointFive Labs](https://www.pointfive.co/blog/introducing-pointfive-labs)

September 16, 2026

- ### [Deployed and Forgotten: LLM Cost Optimization on Bedrock, Microsoft Foundry, and Google Cloud](https://www.pointfive.co/blog/llm-cost-optimization-cost-per-successful-task)

October 6, 2026 6 min read

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