Edit/Write tool should auto-read files instead of erroring

Problem

The Edit and Write tools require that a file has been Read first, otherwise they fail with an error. When this happens, the model must:

1. Attempt Edit → get error ("You must read the file before editing")
2. Call Read on the file
3. Re-attempt the Edit

This wastes 3 tool calls for what should be 1. It burns tokens, increases latency, and provides zero value to the user.

Expected Behavior

If the Edit/Write tool detects the file hasn't been read yet, it should automatically read it internally before applying the edit — not error out and force a round-trip.

The tool already knows which file is being edited. It already has the ability to read files. There is no reason to surface this as an error.

Prior Issues

• #4230 (closed 2025-08-19) — "Write tool should auto-read files instead of requiring explicit read first"
• #16546 (closed) — "Model attempts file edits without reading file first, wasting tokens and time"

Both were closed but the problem persists as of 2025-03 on Claude Opus 4.6. The underlying design issue (error instead of auto-read) was never addressed.

Impact

• Token waste: 3 tool calls instead of 1, every time this occurs
• Latency: Additional round-trips for no user benefit
• User frustration: The system knows exactly what to do but refuses to do it

Environment

• Claude Code version: latest (2025-03)
• Model: Claude Opus 4.6
• Platform: Windows 11