Fifth piece of the Apple Intelligence tool-calling work (see
/Users/rune/.claude/plans/apple-intelligence-tool-calling-plan.md).
Once capabilities.tools flips to true for Apple On-Device (step 7,
not done yet), effectiveSystemPrompt's modelSupportsTools gate would
re-include the user's custom prompt and Agent Skills content — the
same two contributors that blew Phase 1's 4K context budget before
that gate existed (16,377/4,096 tokens on a trivial first message).
Measured the actual tool-usage guidance block instead of assuming it
also needed shortening: ~400 tokens, small enough to keep as-is, so no
separate condensed variant was needed — just keep excluding the two
genuinely large pieces specifically for Apple.
Dormant until step 7: modelSupportsTools is still false for Apple
today, so this has zero behavior change yet. No new tests —
effectiveSystemPrompt has no existing coverage (instance state, not
pure logic) and this change doesn't reduce what's already there.
rune
24bf23e71b