LLM selection for agents

Resolve constraints in this sequence. Each step narrows the candidate set; never widen it later. Everything is over the ConvAI REST API (host https://api.elevenlabs.io, header xi-api-key: $API_KEY).

1. Explore the agent. Read the current LLM, workflow, and tools with GET /v1/convai/agents/$AGENT_ID?branch_id=$BRANCH_ID first.
2. Region (infrastructural, non-negotiable). Determine deployment topology. EU and India customers hit isolated deployments with restricted model lists that apply to all tiers. A model hidden by region cannot be enabled; do not offer to.
3. Compliance entitlements (contract-gated). If the workspace requires HIPAA, PCI, or ZRM, filter to compliant models only. These are workspace-level flags managed by sales/CSMs, never self-serve.
4. Capability fit (intelligence / latency / cost). Within whatever survives steps 1-3, recommend on task requirements.

If a constraint in step 2 or 3 eliminates the model the user wanted, say so plainly and route to their CSM or a support form. Do not present a capability recommendation that violates a hard constraint.

Step 1: region gate