[DOCS] Missing Documentation for Built-in 'Plan' / 'Explore' Subagent

Documentation Type

Missing documentation (feature not documented)

Documentation Location

The feature should be documented on the Subagents page: https://docs.claude.com/en/docs/claude-code/sub-agents. The feature was mentioned in the changelog (2.0.24 - Introducing the Explore subagent.) but not documented further.

Section/Topic

The Subagents page needs a new section detailing the built-in subagents provided with Claude Code, specifically the "Plan" or "Explore" subagent.

Current Documentation

The documentation on the subagents page focuses exclusively on how to create custom subagents. There is no mention of any built-in subagents like "Plan" or "Explore".

What's Wrong or Missing?

The documentation completely lacks information about the built-in "Plan" subagent (also referred to as the "Explore" subagent). This feature appears to have been added in version 2.0.24. Users have no official way of knowing what this subagent does, what tools it uses, or how to invoke it effectively. There is also no clarification on the confusing naming ("Plan" vs. "Explore").

Suggested Improvement

A new section should be added to the Subagents documentation page titled "Built-in Subagents". This section should document the "Plan" / "Explore" subagent.

Based on querying the agent itself, the documentation should include:

• Purpose: It's a fast, specialized, read-only agent for codebase exploration and analysis.
• Core Capabilities:
• File pattern matching (Glob)
• Code searching (Grep)
• Answering architectural questions (Read)
• Directory mapping and project structure analysis (Bash)
• Available Tools: Glob, Grep, Read, Bash.
• Parameters: It accepts a thoroughness parameter with levels: "quick", "medium", and "very thorough".
• Clarification: Explicitly state that it is a read-only agent that does not modify code. Also, clarify the naming convention, noting that it's referred to as both "Plan" and "Explore" but serves as an exploration/analysis tool.
• Example Usage:

> Use the Plan subagent to get an overview of the 'src' directory with medium thoroughness.

Impact

High - Prevents users from using a feature

Additional Context

I had to query the agent to learn about its own functionality. Here is the transcript of that interaction, which can be used to write the official documentation:

My Query:

> use the "Plan subagent" (which is built in) and tell me what it does

Claude Code's Response:

⏺ Plan(Explore current directory structure)
⎿  Done (3 tool uses · 9.3k tokens · 12.9s)

⏺ What the Plan Subagent Does

Based on that execution and the tool specification, the Plan subagent is a fast, specialized agent for
codebase exploration and analysis. Here's what it does:

Core Capabilities

1. File Pattern Matching - Find files using glob patterns (e.g., src/**/*.tsx)
2. Code Search - Search for keywords across the codebase (e.g., "API endpoints")
3. Codebase Questions - Answer architectural questions (e.g., "how do API endpoints work?")
4. Directory Mapping - Explore and summarize project structure

Available Tools

- Glob - for file pattern matching
- Grep - for content searching
- Read - for examining files
- Bash - for shell operations

Thoroughness Levels

You can specify how deep it should search:
- "quick" - Basic searches (what I just used)
- "medium" - Moderate exploration
- "very thorough" - Comprehensive analysis across multiple locations

Key Distinction

This is read-only exploration. It doesn't modify code - it just analyzes, searches, and reports back. It's
designed to be fast and efficient for understanding codebases without making changes.

The naming is slightly confusing - despite being called "Plan", it's essentially a codebase
explorer/analyzer, not a task planner. The description even notes it's the same as the "Explore" subagent.