[DOCS] Fine-grained tool streaming docs still describe provider opt-in behavior

Documentation Type

Incorrect/outdated documentation

Documentation Location

https://code.claude.com/docs/en/env-vars

Section/Topic

CLAUDE_CODE_ENABLE_FINE_GRAINED_TOOL_STREAMING in the environment variables reference

Current Documentation

The environment variables reference currently says:

CLAUDE_CODE_ENABLE_FINE_GRAINED_TOOL_STREAMING | Controls whether tool call inputs stream from the API as Claude generates them.

The same entry describes provider-specific enablement:

Enabled by default on the Anthropic API. On Bedrock and Vertex, enabled per model where the deployed container supports it. Set to 0 to opt out. Set to 1 to force on when routing through a proxy via ANTHROPIC_BASE_URL, ANTHROPIC_VERTEX_BASE_URL, or ANTHROPIC_BEDROCK_BASE_URL. Off by default on Foundry and gateway connections

The page also says telemetry opt-out disables feature-flag fetching:

DISABLE_TELEMETRY | Set to 1 to opt out of telemetry. Telemetry events do not include user data like code, file paths, or bash commands. Also disables feature-flag fetching with the same effect as DISABLE_GROWTHBOOK, so some flagged features may be unavailable

What's Wrong or Missing?

Claude Code v2.1.154 says streaming tool execution is now always enabled, including when telemetry is disabled and on Bedrock, Vertex, and Foundry. The current env var entry still describes the older feature-flag/provider rollout model.

That leaves three outdated implications:

A. Bedrock and Vertex still sound conditional

The docs say fine-grained tool streaming is enabled only "per model where the deployed container supports it," but the v2.1.154 release note says streaming tool execution is now always enabled on Bedrock and Vertex.

B. Foundry still sounds disabled by default

The docs explicitly say the feature is off by default on Foundry, which contradicts the v2.1.154 release note.

C. Telemetry-disabled behavior is not clarified

The docs say DISABLE_TELEMETRY disables feature-flag fetching and can make flagged features unavailable. Since v2.1.154 removed the feature-flag dependency for streaming tool execution, users need to know that disabling telemetry no longer disables this behavior.

Suggested Improvement

Update the CLAUDE_CODE_ENABLE_FINE_GRAINED_TOOL_STREAMING entry to describe the current default.

Suggested replacement:

Tool call inputs stream from the API as Claude generates them. This is enabled by default across Anthropic API, Amazon Bedrock, Google Vertex AI, and Microsoft Foundry connections, including when telemetry or feature-flag fetching is disabled. Set CLAUDE_CODE_ENABLE_FINE_GRAINED_TOOL_STREAMING=0 to opt out if your proxy or gateway cannot handle streamed tool input fields.

If CLAUDE_CODE_ENABLE_FINE_GRAINED_TOOL_STREAMING=1 is still useful for a specific gateway compatibility path, document that as an override for gateway/proxy setups rather than as the way to force-enable Bedrock, Vertex, or Foundry.

Impact

Medium - Makes feature difficult to understand

Additional Context

Affected Pages:

| Page | Line(s) | Context |
|------|---------|---------|
| https://code.claude.com/docs/en/env-vars | 180 | CLAUDE_CODE_ENABLE_FINE_GRAINED_TOOL_STREAMING still describes Anthropic-only default enablement, conditional Bedrock/Vertex enablement, and Foundry/gateway default-off behavior |
| https://code.claude.com/docs/en/env-vars | 291 | DISABLE_TELEMETRY says feature-flag fetching is disabled and flagged features may be unavailable, but streaming tool execution is no longer behind that flag as of v2.1.154 |

Total scope: 1 page affected

Version context: Claude Code v2.1.154 changelog entry: "Streaming tool execution is now always enabled, including when telemetry is disabled or on Bedrock/Vertex/Foundry (previously behind a feature flag)."