wiki-ingest: Multi-Agent System Reliability

wiki/concepts/Fitness-Function.md

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+# Fitness Function
+
+## Definition
+A metric used in the Knock-out multi-agent pattern to evaluate how well each agent performs a task. The function determines which agents survive and which are eliminated. It can be deterministic (e.g., unit tests, exact match) or LLM-based (e.g., quality scoring).
+
+## Role in Multi-Agent Knock-out
+- Evaluates output of each agent
+- Produces a score or boolean pass/fail
+- Used to rank agents and identify worst performers
+- Guides the selection/elimination process
+
+## Key Properties
+- Must be fast — if humans need to verify all branches, the process is too slow
+- Should be deterministic where possible (unit tests over LLM judgment)
+- Can be composite: multiple criteria combined into single score
+- Is where "Evals" come in (critical infrastructure for agent development)
+
+## Examples
+- Unit test pass rate
+- Exact string match against expected output
+- LLM-based quality scoring (with rubric)
+- Latency or token cost as secondary factors
+
+## Related Concepts
+- [[Genetic Algorithms]]
+- [[Multi-Agent Knock-out]]
+- [[Validator]]
+- [[Evals]]