Operational Semantics for CATS Metric Consumption

The CATS framework introduces computing-related information into traffic steering decisions. Existing work defines how such metrics are represented, distributed, and used within the CATS architecture. However, it does not fully address whether a metric remains suitable for use at the point of consumption. This document introduces a set of operational semantics for CATS metrics, including Freshness, Operational acceptability, and Assurance exposure. These semantics describe whether a metric remains temporally aligned with the underlying condition, whether it remains suitable for operational use in steering, and whether degraded consumption is externally visible to management or OAM functions. The document further explains how these semantics apply across centralized, distributed, and hybrid deployments, including cases where different metric sources contribute under different conditions. The goal is to provide a consistent basis for interpreting metric usability in CATS without introducing a new metric level or prescribing a single derivation method.