[BUG] Agent tool doesn't stick to given subtask

Bug Description

The Agent tool will frequently ignore the goal claude code gave it - or at least not stop there - and instead it thinks it has to solve the main task that claude code itself was meant to solve. For example, claude code might invoke Task(Find interpreter load_definitions), and then the sub-agent starts editing files until the problem is solved, rather than just reporting where load_definitions is.

This is a bit annoying because you don't get the same feedback from or control over the subagent as you get from claude code itself, so it's harder to steer.

Steps to Reproduce

This has happened multiple times to me when claude code chose to use the subagent to find where specific behavior is defined

Expected Behavior

The subagent should just do its stated goal and then stop

Actual Behavior

The subagent continued until the overall problem was solved