Do you use the official harness? OpenAI's models are generally best in class for token efficiency. It seems to me like they push for that much more than their competitors.
I think some combination of:
1) Using 1 thread for everything
2) Reviving old threads which are no longer in cache
3) Really broad prompts on badly vibecoded codebases, so model spends huge amount of time tracking down whatever you're trying to do.
4) Non-coding workflow which is more output than input heavy
5) (Less likely IMO) Intelligent use of many passive CI/cron-like scans. E.g. regular security, quality etc scans. Automated issue resolution/PR
Just a guess. I think 3 is likely the primary reason.
You can literally go all day every day with multiple threads with Sol on the Codex 100/month plan IME
I generally agree with those reasons, although using a single thread may be less of an issue than it seems because of context compacting which should happen automatically when you're near the limit.
Token efficiency is near meaningless when the workload is input-heavy. It can't always just choose to read less, depending on the task.
I can have cheaper agents do the reading but it's not appropriate for all use cases because they'll misjudge and choose the wrong things to emphasize, summarize, extract for the bigger model.
I use new threads if relevant old one is uncached. (Often using a skill or doc for handoff instead of requiring full context gathering again.)
I get involved in architecture and specific implementation direction. The codebase is 8 years old and mostly handwritten.
Mostly coding. Some QA.
No cron/CI agents.
The problem is also that at a lot of code bases are not designed around LLMs and their token usage.
If you have a monolete codebase, you need to clearly define in the prompt what modules are involved. And even then, your wasting tokens with the first 1 or 2 steps where it needs to located the modules.
if you have a github codebase, with a lot of your code into nice little repos, its even worse because then the model needs to pull data, and a ton of more steps.
Most people do not open their coding agents in the module directories because "it may need something out of it".
I mean, we used to program by creating utils directories to deal with repetitive code but models (a) find it and use it (but it cost steps and tokens to read), (b) do not realize it there and make their own version of whatever or (c) combination of both.
And ironically, i feel like we need to give up on this idea of reusable code, and literally keep things into single modules, with as minimum external dependencies. That in return reduces searches and thus steps/tokens burn. But very few agents / harnesses have proper implementation of groups/projects and sub-module structures. Aka they only open a single dir, so your then forced to create dozens of tabs > per dir > cli ...
2. That is also a issue if you open multiple agents. Maybe now your working in A, B but C, D, E are not doing anything. And their cache expires... Now you go back to D because A, B needed to be done, and now your paying Cache Write + Input cost.
Its hard to have a good flow to keep things cached, when to really /new and when to not have it expire (and that assumes there are no issue with the provider moving your session around and forcing new cache hits. MiMo did that a lot in the past).
Something that i also advice more and more to people. Get a microphone, download openwisper and talk (text to prompt). You tend to give more information vocally, then writing as its in our habit of programming to not be verbose. Its like people are afraid of long prompts. While just talking to the LLM tend to give it much more information to work with, often resulting it being able to skip steps.