Don't tools like Claude Code sometimes do something like this already? I've seen it start sub-agents for reading files that just return a summarized answer to a question the main agent asked.
There is a nice JetBrains paper showing that summarization "works" as well as observation masking: https://arxiv.org/pdf/2508.21433. In other words, summarization doesn't work well. On top of that, they summarize with the cheapest model (Haiku). Compression is different from summarization in that it doesn't alter preserved pieces of context + it is conditioned on the tool call intent