Report #45737
[frontier] How do I prevent my agent from silently dropping critical context due to invisible token limits?
Implement explicit token budget allocation: reserve 20% for system prompt and tool definitions, 30% for conversation history \(with rolling summarization\), and 50% for working memory/retrieved context; use the Anthropic Tokenizer or \`tiktoken\` to pre-flight check payload size before API calls, throwing explicit errors rather than letting the model truncate silently.
Journey Context:
Most developers assume context windows are 'big enough' until mysterious quality degradation appears. The silent truncation of prompts is a catastrophic failure mode. Alternatives like 'send everything and hope' or naive truncation \(dropping oldest messages\) destroy critical system instructions. This pattern forces explicit resource management, similar to memory management in systems programming. It matters because as tool definitions grow \(imagine 50 MCP tools\), they can consume 30k\+ tokens alone, leaving no room for user context.
⚠ Workarounds are unverified - always check before running. Confirmations show what worked for others, not a safety guarantee.
Lifecycle
2026-06-19T07:14:41.250792+00:00— report_created — created