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tedsandersyesterday at 6:34 PM3 repliesview on HN

>GPT-5 showed significant improvement only in one benchmark domain - which is Telecom. The other ones have been somehow overlooked during model presentation - therefore we won’t bother about them either.

I work at OpenAI and you can partly blame me for our emphasis on Telecom. While we no doubt highlight the evals that make us look good, let me defend why the emphasis on Telecom isn't unprincipled cherry picking.

Telecom was made after Retail and Airline, and fixes some of their problems. In Retail and Airline, the model is graded against a ground truth reference solution. Grading against a reference solution makes grading easier, but has the downside that valid alternative solutions can receive scores of 0 by the automatic grading. This, along with some user model issues, is partly why Airline and Retail scores stopped climbing with the latest generations of models and are stuck around 60% / 80%. I'd bet you $100 that a superintelligence would probably plateau around here too, as getting 100% requires perfect guessing of which valid solution is written as the reference solution.

In Telecom, the authors (Barres et al.) made the grading less brittle by grading against outcome states, which may be achieved via multiple solutions, rather than by matching against a single specific solution. They also improved the user modeling and some other things too. So Telecom is the much better eval, with a much cleaner signal, which is partly why models can score as high as 97% instead of getting mired at 60%/80% due to brittle grading and other issues.

Even if I had never seen GPT-5's numbers, I like to think I would have said ahead of time that Telecom is much better than Airline/Retail for measuring tool use.

Incidentally, another thing to keep in mind when critically looking at OpenAI and others reporting their scores on these evals is that the evals give no partial credit - so sometimes you can have very good models that do all but one thing perfectly, which results in very poor scores. If you tried generalizing to tasks that don't trigger that quirk, you might get much better performance than the eval scores suggest (or vice versa, if your tasks trigger a quirk not present in the eval).

Here's the tau2-bench paper if anyone wants to read more: https://arxiv.org/abs/2506.07982


Replies

fallmonkeyyesterday at 11:03 PM

Appreciated the response! I noticed the same when I ran tau2 myself on gpt-5 and 4.1, where gpt-5 is really good at looking at tool results and interleaving those with thinking, while 4.1/o3 struggles to decide the proper next tool to use even with thinking. To some extent, gpt-5 is too good at figuring out the right tool to use in one go. Amazing progress.

DoctorOetkertoday at 2:50 AM

This sounds very vague, what does scoring good at Telecom mean?

Can we get some (hypothetical) examples of ground truths?

For example for the Airline domain, what kind of facts are these ground truth facts? All the airports, the passenger lines between them, etc? Or does it mean detailed knowledge of the airplane manuals for pilots, maintenance, ...?

blndrtyesterday at 7:51 PM

Haha, I guess my little sarcasm just earned us a masterclass! Thanks a lot for sharing your insights — really appreciate it!