[BUG] Multiple Agent(type)entries in agenttools:` frontmatter — only last entry survives

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?

When a plugin agent's tools: frontmatter field contains multiple Agent(type) entries (comma-separated), only the last entry is retained as an available agent type. All preceding entries are silently dropped.

Example orchestrator.md:
tools: Agent(my-plugin:agent-a), Agent(my-plugin:agent-b), Agent(my-plugin:agent-c)

At runtime, only my-plugin:agent-c is available. Attempts to spawn agent-a or agent-b fail with:
Error: Agent type 'my-plugin:agent-a' not found. Available agents: my-plugin:agent-c

What Should Happen?

All three agent types (my-plugin:agent-a, my-plugin:agent-b, my-plugin:agent-c) should be available for spawning.

Error Messages/Logs

Error: Agent type 'my-plugin:agent-a' not found. Available agents: my-plugin:agent-c

Steps to Reproduce

1. Create a plugin with an orchestrator agent whose frontmatter is:

---
name: orchestrator
tools: Agent(my-plugin:agent-a), Agent(my-plugin:agent-b), Agent(my-plugin:agent-c)
---

1. Also define agent-a, agent-b, and agent-c in the plugin.
2. Run the orchestrator: claude --agent my-plugin:orchestrator
3. Ask the orchestrator to invoke agent-a via the Agent tool.

Expected: agent-a spawns successfully.
Actual: Error: Agent type 'my-plugin:agent-a' not found. Available agents: my-plugin:agent-c

Workaround: Replace all Agent(type) entries with the bare Agent keyword:
tools: Agent
This grants access to all agent types and unblocks the pipeline.

Claude Model

Sonnet (default)

Is this a regression?

I don't know

Last Working Version

_No response_

Claude Code Version

2.1.145

Platform

Anthropic API

Operating System

macOS

Terminal/Shell

Terminal.app (macOS)

Additional Information

_No response_