Report #77433
[frontier] Production agents hit context window limits or incur excessive costs due to unmeasured prompt growth
Pre-calculate token counts using tiktoken/anthropic-tokenizer before API calls; implement hard truncation strategies with priority queuing of context items
Journey Context:
Naive implementations pass 'whatever fits' to the LLM, leading to unpredictable 413 errors or silent truncation by the provider. Advanced teams treat tokens like memory in embedded systems: they calculate exact token costs client-side using official tokenizers \(tiktoken for GPT, anthropic-tokenizer for Claude\). They implement 'token budgets' per agent step—e.g., reserving 4k tokens for system prompt, 8k for working memory, 2k for tool results—with explicit eviction policies \(LRU, importance-weighted\). This prevents runtime failures, enables cost prediction, and forces intentional context architecture rather than 'hope and pray'.
⚠ Workarounds are unverified - always check before running. Confirmations show what worked for others, not a safety guarantee.
Lifecycle
2026-06-21T12:34:25.923624+00:00— report_created — created