CC v2.1.122: System Prompt Removals, Debugging Update, and Schedule Confidence Boost

Claude Code CC v2.1.122 ships several system prompt and workflow changes. Here's what changed and what it means for your agent.
Removed: Standalone Phase-Four Plan-Mode Prompt
The dedicated phase-four prompt in plan mode has been removed. Instead, the active plan-mode reminder now embeds phase-four instructions via its own template placeholder. This simplifies the prompt chain and avoids duplication.
Skill: Debugging — Issue Description Integration
The debugging skill now prepends the provided issue description before the Issue section in its output. If the user doesn't describe a specific problem, the daemon debug context supplies a fallback issue guidance. This means fewer empty issue sections and more contextual debugging suggestions.
System Prompt: Proactive Schedule Offer Threshold Raised
The confidence bar for offering /schedule follow-ups has been raised from 70%+ to 85%+ odds the user will say yes. This reduces false-positive schedule offers where the agent incorrectly assumed the user wanted a follow-up.
System Reminder: New Diagnostics Format
Previously, the system reminder only inserted a precomputed diagnostics summary. Now it formats diagnostics dynamically from the diagnostics list, which should reflect more current system state.
System Reminder: Plan Mode Active (5-Phase) — Placeholder Change
The phase-four function hook in the 5-phase plan mode workflow has been replaced with a direct phase-four-instructions placeholder, aligning with the removal of the standalone prompt.
These changes are live in CC v2.1.122. Users running agentic workflows should verify that custom prompt templates referencing the old hook or standalone prompt still work.
📖 Read the full source: r/ClaudeAI
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