[BUG] DISABLE_GROWTHBOOK forces Task tools vs cross-session messaging/Remote Control trade-off; no supported per-capability override

Preflight Checklist

• [x] I searched existing issues. Related but distinct: #75577 and #80401.
• [x] This is one configuration/availability bug.
• [x] I re-verified this on the latest Claude Code version immediately before filing.

What's Wrong?

There is no supported way to keep all three of these capabilities available in one Claude Code
process:

1. TaskCreate / TaskGet / TaskList / TaskUpdate
2. native cross-session ListAgents / SendMessage
3. Remote Control

On models matched by the Task gate reported in #75577, normal GrowthBook evaluation can silently
remove the four Task tools. Setting DISABLE_GROWTHBOOK=1 restores those Task tools because the gate
uses its code default, but the current environment-variable documentation says the same global
switch makes Remote Control and cross-session messaging unavailable.

This turns a telemetry/feature-flag control into an unavoidable capability trade-off.

What Should Happen?

Users should be able to enable Task tools without disabling unrelated capabilities. Any one of
these would solve the problem:

• make CLAUDE_CODE_ENABLE_TASKS=1 a true force-enable again;
• provide documented per-capability controls instead of requiring the blanket GrowthBook switch;
• clear the Task model gate; or
• provide another supported Task override plus /doctor observability explaining why a built-in

tool is unregistered.

Steps to Reproduce

Environment used for this report:

• Claude Code: 2.1.226
• OS: macOS 26.5.2 (build 25F84), Darwin 25.5.0, arm64
• Model: claude-sonnet-5
• Authentication: claude.ai subscription / direct Anthropic endpoint
• Session type: fresh interactive top-level session

1. Ensure DISABLE_GROWTHBOOK is not set and start a fresh session on a model currently matched by

the Task gate.

1. Query ToolSearch for select:TaskGet and record whether a schema is returned.
2. Confirm Remote Control eligibility and whether ListAgents is present.
3. Set DISABLE_GROWTHBOOK=1 in a settings env block and start a fresh session.
4. Query ToolSearch for TaskGet again: the Task tools are restored.
5. Query for ListAgents and attempt /remote-control: ListAgents is absent and Remote Control

reports that feature-flag evaluation is required.

Actual Result

• GrowthBook enabled: RC/messaging can be available, but the four Task tools can be silently

unregistered on matched models.

• DISABLE_GROWTHBOOK=1: Task tools are available, but RC and cross-session messaging are disabled.
• There is no documented setting that disables only the Task gate or force-enables Tasks.

Additional Investigation

Read-only inspection of the installed 2.1.226 executable indicates these are separate capability
flags sharing the top-level GrowthBook dependency, rather than one shared capability flag. That
suggests a narrower override is architecturally possible. I can provide exact sanitized binary
hashes and predicate excerpts if useful.

Official docs:

• https://code.claude.com/docs/en/env-vars
• https://code.claude.com/docs/en/cross-session-messaging
• https://code.claude.com/docs/en/remote-control

Related issues:

• #75577
• #80401
• #34255
• #33041
• #32982

Impact

Workflows that depend on Task tools for local atomicity cannot also use native peer coordination
and Remote Control in a supported configuration. The failure is silent: tools disappear from the
registry, so skills and agents receive a smaller toolset without an actionable diagnostic.

Logs

No secrets or full environment dump attached. Sanitized debug excerpts and a minimal reproduction
transcript are available on request.