This afternoon, while reading through the MCP docs, I noticed that Claude's official documentation suggests copying the full text of documents longer than 50,000 characters straight into the conversation, which struck me as unreasonable (way too many input tokens). Curious whether today's large models can actually handle that, I gave it a try with Doubao — and the context overflowed. Trae's Builder also warned that it only supports prompts up to 6,000 characters. I normally ask questions with documents, so pasting content directly into the chat felt like "a battle fought with such deep pockets" — a novelty. In the end I had the AI tally up the context window sizes of mainstream large models.