[Bug] Subagents not inheriting MCP tools from plugin-defined agents

Bug Description

I have a marketplace plugin which defines an agent that want to use the MCP tool of the plugin. But in pratice, the subagent does not receive the MCP tools, is it a known bug?

The documentation says subagents CAN access MCP tools, but in practice, the ticket-analyzer subagent is NOT receiving them.

This appears to be a bug rather than a documented limitation. Here's what we know:

| Aspect | Expected (per docs) | Actual |
|----------------------------------------------|---------------------|------------------|
| MCP tools in parent session | Available | Works |
| MCP tools listed in agent tools: frontmatter | Should grant access | Listed correctly |
| MCP tools in subagent session | Should be available | Not available |

Possible causes:

1. Plugin-defined agents may have different behavior - The agent is defined in a marketplace plugin (hivebrite-claude-plugins), not in .claude/agents/. The documentation may only apply to user-defined agents.
2. MCP tool naming mismatch - The agent lists mcp__plugin_hivebrite_atlassian__getJiraIssue but the subagent mentioned plugin_hivebrite_atlassian:getJiraIssue (different separator). This could indicate a naming convention issue.
3. Plugin MCP servers not inherited - MCP servers defined in plugin .mcp.json files may not be accessible to subagents spawned from those same plugins.

Environment Info

• Platform: darwin
• Terminal: iTerm.app
• Version: 2.0.71
• Feedback ID: afe0a885-b950-465b-9a7d-c3fc3e2b67ee

Errors

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