Tool Transition Fusion

Problem

Many tool sequences are nearly deterministic. After a search, the agent almost always fetches one of the top results; after a database lookup, it almost always formats and writes a row. These transitions are paid for over and over: each step is a model call, each decision an opportunity for the planner to mis-pick. The agent's intermediate decoding errors and per-step latency dominate the trajectory cost even though the team could see, from the telemetry alone, that the transition was effectively fixed.

Solution

Sweep tool-call telemetry for transitions P(Y|X) above a threshold (e.g. 0.8). Wrap qualifying X-then-Y pairs in a composite tool whose signature is X's input and Y's output. Add the composite to the catalog; leave X and Y available for edge cases. Re-run the sweep periodically as task mix shifts. Document why each composite exists so a later reviewer understands the fusion was telemetry-driven, not author intuition.

When to use

• Sufficient tool-call telemetry exists to estimate transition probabilities.
• Per-step latency or decoding-error rate is a measurable cost driver.
• A clear majority transition (>0.8 conditional probability) recurs across many sessions.