Impact of Shell Variation on MTI Profiles

Quantify how much variation in runtime configuration (the Shell) changes a Model Temperament Index (MTI) temperament profile for a fixed model Core.

Background

The MTI framework defines an agent as a Core (architecture and weights) plus a Shell (runtime configuration, including system prompt, temperature, tools, and interaction history). In this paper, each Core is evaluated under a single canonical Shell (temperature = 0, default system prompt).

Understanding the extent to which Shell changes affect measured temperament is necessary to separate Core‑level disposition from deployment‑level modulation and to support reliable agent‑level profiling.