Tool-Result Eviction

Problem

Raw tool outputs are the largest and most disposable thing in an agent's context. Keeping every observation verbatim crowds the window, raises cost, and buries the signal the agent actually reasoned over; but deleting a tool turn entirely loses the record that the call was made and what it concluded, which the agent may need to avoid repeating work or to justify its actions.

Solution

Treat tool observations as evictable. When a tool result has been consumed — its needed values extracted into the agent's reasoning or into external memory — replace the raw payload in the working context with a short marker that records the call, its target, and the one-line conclusion ('read config.yaml: 3 services defined', 'searched docs: no rate-limit setting found'). Keep the marker so the agent does not re-issue the call; offload the full payload to external storage if it might be needed verbatim again. Apply eviction lazily (oldest-consumed first) or eagerly (immediately after extraction) depending on how tight the window is. Manus and the Chinese context-engineering literature describe this as tool clearing.

When to use

• Tool observations are large relative to the context window.
• Most results are consumed once and not needed verbatim again.
• Window pressure or per-call cost is a binding constraint.
• You can write a faithful one-line marker for each consumed result.