[BUG] /agents displays "sonnet" for subagents that inherit model from parent

Preflight Checklist

• [x] I have searched existing issues and this hasn't been reported yet
• [x] This is a single bug report (please file separate reports for different bugs)
• [x] I am using the latest version of Claude Code

What's Wrong?

The /agents command displays "sonnet" as the model for subagents spawned via the Task tool when no model is explicitly specified, even though the subagent actually inherits and runs on the parent model.

When spawning a general-purpose subagent without specifying a model, the subagent correctly self-reports as running on the inherited model (e.g., Opus 4.5), but /agents incorrectly shows "sonnet".

This is a visual/display bug only—the subagent runs on the correct inherited model at runtime.

What Should Happen?

According to the official documentation, the general-purpose subagent model behavior is:

| Attribute | Value |
|-----------|-------|
| Model | Inherits from main conversation |

The /agents UI should reflect this by displaying either:

• The actual inherited model name (e.g., "opus" when parent is Opus 4.5)
• Or "inherit" to indicate the model is inherited from parent

Error Messages/Logs

# No error - this is a display bug
# /agents shows: model: sonnet
# Subagent self-reports: Claude Opus 4.5 (claude-opus-4-5-20251101)

Steps to Reproduce

1. Start Claude Code with Opus 4.5 as the main model
2. Ask Claude to spawn a general-purpose subagent without specifying a model:

``
start a general-purpose subagent and tell me what model it is running
``

1. The subagent self-reports as Claude Opus 4.5 (claude-opus-4-5-20251101)
2. Run /agents command
3. Observe that the subagent shows sonnet as its model, contradicting both the runtime behavior and the documentation

Claude Model

Opus

Is this a regression?

I don't know

Last Working Version

_No response_

Claude Code Version

2.1.17 (Claude Code)

Platform

Anthropic API

Operating System

macOS

Terminal/Shell

Terminal.app (macOS)

Additional Information

Documentation Reference: https://code.claude.com/docs/en/sub-agents#general-purpose

The documentation explicitly states the general-purpose subagent "Inherits from main conversation" for its model. The /agents display should reflect this documented behavior.

Related Issues:

• #15319 covers a similar display bug for agentSettings overrides, but this issue is about the default inheritance behavior not being reflected in the UI
• #13434 mentions wrong default subagent model display

This appears to be a UI-level bug where /agents displays a hardcoded or default "sonnet" value instead of querying the actual resolved model.