When an agent is editing a proposed plan, it’s painfully slow. Tool calls are made inconsistently, and the agent ends up running a mix of sed, xxd, etc to make edits
Steps to Reproduce
Use plan mode to create a plan, then provide the agent with feedback on the plan that will result in changes.
Expected Behavior
The agent should quickly update the plan, as opposed to the behavior I’m seeing where it takes something like 10 seconds per edit. Also edits should proceed quickly using tool calls, while I see cursor reaching for command line tools and struggling to succeed.
This looks like it might be a regression of a bug we already fixed. The model was trying to use shell utilities like sed, xxd, and so on to edit plan files instead of making the correct tool calls. That fix shipped a while ago, so seeing this again on 2.5.17 is worrying.
To narrow it down:
Does this happen when you open the project directly in Windows, not through WSL? We’re trying to figure out whether the WSL layer is affecting this.
My entire project lives inside the ubuntu distro I use for WSL, and it looks like the plans all live in the linux filesystem too. Crossing the linux/windows FS barrier does effect performance, but I just checked and in my windows home directory the newest plan is from January 5th.
Thanks for clarifying. Since the project and plans live fully inside the Linux filesystem, that rules out a cross-filesystem issue.
This looks like a regression of a previously fixed bug where the agent used shell utilities instead of tool calls when editing plans. I passed this to the team along with your request ID.
As a temporary workaround, try switching from Auto to a specific model, like Claude 4.6 Sonnet, and see if the issue still happens. That’ll help confirm whether it’s related to Auto model selection.
Tried a simple plan, request id: 621ff57e-17b1-44e2-a85a-1456f2afdcac
Seemed to edit properly but I did notice this in the agent transcript: {"role":"assistant","message":{"content":[{"type":"text","text":"**Revising Path Strings**\n\nI've pinpointed the `StrReplace` failure: a classic absolute path blunder! Backslashes and Linux don't mix. The path should use forward slashes. I am correcting the path string now and will rerun the operation. I'm hoping for a successful outcome this time.\n\n\n**Fixing File Paths**\n\nI've got the path string updated now, using the proper forward slashes. A simple oversight, but these small details are often the culprits. Rerunning `StrReplace` shortly; hoping this correction will finally yield the desired results, and I'll adjust the to-do list accordingly.\n\n\n"}]}}
I’ll keep this updated as I have a chance to do some more testing.