[DOCS] Model configuration docs omit `_MODEL_NAME`/`_DESCRIPTION` support for custom `ANTHROPIC_BASE_URL` gateways

Documentation Type

Incorrect/outdated documentation

Documentation Location

https://code.claude.com/docs/en/model-config

Section/Topic

Customize pinned model display and capabilities in Model configuration, plus Model selection in LLM gateway configuration

Current Documentation

The docs currently say:

These variables only take effect on third-party providers such as Bedrock, Vertex AI, and Foundry. They have no effect when using the Anthropic API directly.

And the gateway page says:

If you have configured custom model names in your gateway, use the environment variables documented in Model configuration to match your custom names.

What's Wrong or Missing?

Changelog v2.1.118 says: The /model picker now honors ANTHROPIC_DEFAULT_*_MODEL_NAME/_DESCRIPTION overrides when using a custom ANTHROPIC_BASE_URL gateway.

The current docs do not explain that these display-label overrides now work for custom gateways configured through ANTHROPIC_BASE_URL. Instead, the Model configuration page still scopes the _NAME and _DESCRIPTION variables to Bedrock, Vertex AI, and Foundry-style third-party providers, which makes the current behavior for custom gateways unclear or misleading.

That leaves gateway administrators without explicit guidance on how to make gateway-routed models show friendly names and descriptions in /model.

Suggested Improvement

Update the Model configuration page to explicitly include custom ANTHROPIC_BASE_URL gateways in the scope of ANTHROPIC_DEFAULT_{OPUS,SONNET,HAIKU}_MODEL_NAME and _DESCRIPTION.

Add a short gateway example such as:

export ANTHROPIC_BASE_URL='https://gateway.example.com'
export ANTHROPIC_DEFAULT_SONNET_MODEL='my-gateway/claude-sonnet-4-6'
export ANTHROPIC_DEFAULT_SONNET_MODEL_NAME='Sonnet via Gateway'
export ANTHROPIC_DEFAULT_SONNET_MODEL_DESCRIPTION='Claude Sonnet 4.6 routed through the internal gateway'

Also update the LLM gateway Model selection section to say that these variables can control both the routed model ID and the /model picker's display label/description for custom gateway deployments.

Impact

Medium - Makes feature difficult to understand

Additional Context

Affected Pages:

| Page | Context |
|------|---------|
| https://code.claude.com/docs/en/model-config | Defines _MODEL_NAME and _DESCRIPTION behavior, but currently limits the scope to Bedrock, Vertex AI, and Foundry |
| https://code.claude.com/docs/en/llm-gateway | Tells gateway users to use Model configuration env vars, but does not say these overrides now affect /model labels for custom ANTHROPIC_BASE_URL gateways |
| https://code.claude.com/docs/en/env-vars | Lists ANTHROPIC_DEFAULT_{OPUS,SONNET,HAIKU}_MODEL_{NAME,DESCRIPTION} but does not clarify gateway-specific usage |

Total scope: 3 pages affected

Source: Changelog v2.1.118

Exact changelog entry: The /model picker now honors ANTHROPIC_DEFAULT_*_MODEL_NAME/_DESCRIPTION overrides when using a custom ANTHROPIC_BASE_URL gateway