Cut Coding Agent Token Use With Better Tool Output
The New Stack, Monday, August 31st, 2026
Verbose JSON makes agents pay for field names hundreds of times; tool output format is an engineering decision.
Most of what teams pay for in agentic coding is not the pull request but everything the agent read to produce it, and a often-overlooked lever is the format in which developer tools hand data back.
When a tool returns a long list of similarly shaped records, verbose JSON charges the model repeatedly for field names, quotes, and structural syntax.
The article is careful not to condemn JSON, which remains widely supported and more compact for nested or irregular data; the narrow question is what to do with large uniform collections.
Token-Oriented Object Notation (TOON) is offered as one answer, keeping a schema-like header for a uniform array and emitting each record as a row - a lossless encoding of the JSON data model that also gives the model a predictable field set.