A returns agent calls lookup_order several times per session. Each call appends the tool's full 40+ field response to the conversation, although a return decision uses about five of those fields. Long sessions run short of context and the agent starts overlooking return-window dates. What is the most effective change?

Answer: C — Trim each lookup result to the return-relevant fields before it is appended to the conversation

Tool results stay in context and are re-sent on every turn, so trimming them to the relevant fields before they accumulate removes the noise at its source. (A) only delays the problem and leaves the relevant fields diluted. (B) compresses exactly the dates and amounts the decision needs. (D) breaks conversational coherence; each request should carry the complete history.