I'm convinced now that the key to getting useful results out of coding agents (Claude Code, Codex CLI etc) is having good mechanisms in place to help those agents exercise and validate the code they are writing.
At the most basic level this means making sure they can run commands to execute the code - easiest with languages like Python, with HTML+JavaScript you need to remind them that Playwright exists and they should use it.
The next step up from that is a good automated test suite.
Then we get into quality of code/life improvement tools - automatic code formatters, linters, fuzzing tools etc.
Debuggers are good too. These tend to be less coding-agent friendly due to them often having directly interactive interfaces, but agents can increasingly use them - and there are other options that are a better fit as well.
I'd put formal verification tools like the ones mentioned by Martin on this spectrum too. They're potentially a fantastic unlock for agents - they're effectively just niche programming languages, and models are really good at even niche languages these days.
If you're not finding any value in coding agents but you've also not invested in execution and automated testing environment features, that's probably why.
At the most basic level this means making sure they can run commands to execute the code - easiest with languages like Python, with HTML+JavaScript you need to remind them that Playwright exists and they should use it.
The next step up from that is a good automated test suite.
Then we get into quality of code/life improvement tools - automatic code formatters, linters, fuzzing tools etc.
Debuggers are good too. These tend to be less coding-agent friendly due to them often having directly interactive interfaces, but agents can increasingly use them - and there are other options that are a better fit as well.
I'd put formal verification tools like the ones mentioned by Martin on this spectrum too. They're potentially a fantastic unlock for agents - they're effectively just niche programming languages, and models are really good at even niche languages these days.
If you're not finding any value in coding agents but you've also not invested in execution and automated testing environment features, that's probably why.