Write tool never executes: plan writing tasks consume 40-50k tokens without writing a single line to file

Bug Report

Date: 2026-05-19

Environment:

• Claude Code CLI, macOS Darwin 25.4.0
• Model: claude-sonnet-4-6
• Project: onbo-360 (SaaS platform)

What was asked

Write an implementation plan to a file: docs/superpowers/plans/2026-05-19-ra-website-builder.md

Prompt: Read 3 files (CLAUDE.md, HANDOFF.md, spec doc), then write plan to file.

What happened

• Across multiple sessions today (since afternoon), the Write tool never executed
• Each session consumed 40-50k+ tokens in overhead (skill invocations, file reads, bash commands, diagnostic questions)
• Model kept switching to explaining/diagnosing instead of writing
• No plan file was ever created
• In the final session: model said 'Writing now' multiple times but never called the Write tool

Expected behavior

Write tool executes and creates the plan file after reading source files.

Actual behavior

Write tool never fires. Model cycles through: skill invocation → file reads → directory checks → 'Writing now' text → stall → explanation mode → repeat.

Impact

~100k tokens wasted across multiple sessions. Zero output produced. Task completely blocked.

Possible cause (user hypothesis)

Not overhead/reload (context persists across interruptions). Root cause unknown — model appears unable to reach the Write tool call execution step despite having all required context loaded.