Your system prompt is too big

What version of the IDE extension are you using?

26.417.40842

What subscription do you have?

Plus

Which IDE are you using?

VSCode/.Cursor (same)

What platform is your computer?

_No response_

What issue are you seeing?

I am trying Codex (after years of using Cursor and months of Claude Code) and the system prompt looks bloated.

Asking a simple question "what is 2+2" consumes ~13k (13 thousand!) tokens. I don't have any skills, custom prompts, MCPs, my project's agents.md is 30 lines (500 tokens).

I interrogated Codex to tell me how big the system instructions are and it says:

A reasonable estimate for this session is:

* System instructions: 2k-4k
* Web/browsing policy and source-handling rules: 3k-5k
* Developer instructions for coding behavior/style/workflow: 3k-5k
* Tool schemas and tool descriptions: 2k-4k
* AGENTS.md and environment context: 0.5k-1k
* Your actual message: under 100

Pardon my French, this is nuts.

What steps can reproduce the bug?

Ask "What is 2+2" in VScode extension, see this

<img width="199" height="153" alt="Image" src="https://github.com/user-attachments/assets/705af6f7-7556-42e7-8136-9f5b2efa6c21" />

What is the expected behavior?

_No response_

Additional information

_No response_