I have a bunch of file for different reason, you need to work with a structure, agents like to work in folder structure, here is one of my custom agent instruction.
Now i have a agents.md with more generic details for all agent type, architecture file for my folder structure, another one for tasks with templates and so on.
Now i start all my prompt with please search and read/multi-read all .md file
(If i have the file system MCP installed, wich is free and godsend)
My md file has my high level planing, brainstorming files and other complementary file that i keep up to date so that when the AI is done ingesting all the md files he is prepped up to go dig code, write code and chew bubblegum… Mmmm might need some work on the last one. HE MUST CHEW BUBBLE GUM AND HE HAS NO MOUTH (Claptrap kiss no mouth reference)
You need to have them work on small vertical slice that can be built under a 100k token more or less, more than that the agent start to misbehave and you need to fire him.
I have custom architect for building plan, codeseeker, coder, and other more specialised agents.
Build your team, build a structure, in the last 2 month playing with agents and python i learnt more about coding than a full year high school. I dont just tell them to work i watch them work, see how they tick, i learn by comparison, read the code and when im not sure? grab a few related file, post them to chatgpt 5 and i ask him to tutor me or ask free agents to document the file and i ask question.
You dont ask a human to climb a tree even tho he look like a monkey, he might be able to, but still not his best skill. Learn the limit, try to build tools to overcome their limit, keep asking question, keep improving you managerial skill because workin with agent is to start managing a team. Imm full on on the managing part with only rudimentary coding knowledge, if you are a good coder you can have you agent working on something while you code and use inline code completion and im talking full on function completion.
Maybe codex is more for you, there is a lot of agent type, providers each one with their strenght and weakness, experiement.
I really hope you can find your tool, the one adapted to what you want and that you can grow into your tool too, then you become borg! Hmm might be premature on the borg thing. Eh oh well.