Foundation Models Diagnostics

Overview

Foundation Models issues manifest as context window exceeded errors, guardrail violations, slow generation, availability failures, and unexpected output. Core principle 80% of Foundation Models problems stem from misunderstanding model capabilities (3B parameter device-scale model, not world knowledge), context limits (4096 tokens), or availability requirements—not framework bugs.

Red Flags — Suspect Foundation Models Issue

If you see ANY of these, suspect a Foundation Models misunderstanding, not framework breakage:

• Generation takes >5 seconds
• Error: exceededContextWindowSize
• Error: guardrailViolation
• Error: unsupportedLanguageOrLocale
• Model gives hallucinated/wrong output
• UI freezes during generation
• Feature works in simulator but not on device
• ❌ FORBIDDEN "Foundation Models is broken, we need a different AI"
  • Foundation Models powers Apple Intelligence across millions of devices
  • Wrong output = wrong use case (world knowledge vs summarization)