model-selection

# Model Selection Use this skill when the user requests a model, the team configuration contains a saved model preference, or a specialist charter explicitly requires one. ## Resolution Order Apply the first available value: 1. Explicit model requested for the current spawn. 2. Current-session model directive from the user. 3. `.squad/config.json` `agentModelOverrides.{specialist-id}`. 4. `.squad/config.json` `defaultModel`. 5. The specialist charter's explicit model requirement. 6. Runtime automatic selection by omitting the model parameter. An explicit current request always overrides older persistent configuration. Do not invent a model preference from task type alone, and do not pin a hardcoded fallback that can become obsolete. ## Persistent Preferences - Save `defaultModel` or `agentModelOverrides` only when the user explicitly asks for persistence. - Merge model fields into the existing `.squad/config.json`; do not replace unrelated settings. - Use active specialist IDs from `.squad/casting/registry.json`. - Validate a requested model against the runtime's currently supported model list. - To return to automatic routing, remove the applicable override rather than writing an `"auto"` sentinel unless the runtime schema explicitly supports it. ## Spawn Behavior - Pass a model only when resolution steps 1-5 produce a supported value. - Otherwise omit the model parameter and allow the runtime to select. - Preserve the user's requested reasoning effort or context tier only when the runtime supports it. - If a requested model is unavailable, report that failure and fall back to runtime automatic selection unless the user supplied a different fallback. ## Stop Conditions - Stop if the requested model is not supported and no automatic fallback is acceptable. - Stop rather than rewriting configuration when `.squad/config.json` cannot be parsed safely. - Do not benchmark models, estimate billing, or modify specialist responsibilities under this skill.