Purge your Claude Code context window

README.md

Purge your Claude Code context window

Claude Code v2.1.29

Removes all system tools from the context window. Not very useful on its own, but it's a good starting point when developing Subagents. This helps to reclaim up to ~17k tokens (~8.5%) from the context window.

Before

❯ /context
  ⎿  Context Usage
     ⛁ ⛁ ⛁ ⛁ ⛁ ⛁ ⛁ ⛁ ⛁ ⛀   claude-haiku-4-5-20251001 · 19k/200k tokens (10%)
     ⛀ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶
     ⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶   Estimated usage by category
     ⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶   ⛁ System prompt: 2.6k tokens (1.3%)
     ⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶   ⛁ System tools: 16.5k tokens (8.3%)
     ⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶   ⛁ Skills: 61 tokens (0.0%)
     ⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶   ⛁ Messages: 8 tokens (0.0%)
     ⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶   ⛁ Compact buffer: 3.0k tokens (1.5%)
     ⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶   ⛶ Free space: 178k (88.9%)
     ⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛁ ⛀

     Skills · /skills

After

❯ /context
  ⎿  Context Usage
     ⛁ ⛀ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶   claude-haiku-4-5-20251001 · 2k/200k tokens (1%)
     ⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶
     ⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶   Estimated usage by category
     ⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶   ⛁ System prompt: 2.3k tokens (1.2%)
     ⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶   ⛁ Messages: 8 tokens (0.0%)
     ⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶   ⛁ Compact buffer: 3.0k tokens (1.5%)
     ⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶   ⛶ Free space: 195k (97.3%)
     ⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶
     ⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶
     ⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛁ ⛀

---

Tools available to Claude

Source: https://code.claude.com/docs/en/settings#tools-available-to-claude

Claude Code has access to a set of powerful tools that help it understand and modify your codebase:

Tool	Description	Permission Required
AskUserQuestion	Asks multiple-choice questions to gather requirements or clarify ambiguity	No
Bash	Executes shell commands in your environment	Yes
TaskOutput	Retrieves output from a background task (bash shell or subagent)	No
Edit	Makes targeted edits to specific files	Yes
ExitPlanMode	Prompts the user to exit plan mode and start coding	Yes
Glob	Finds files based on pattern matching	No
Grep	Searches for patterns in file contents	No
KillShell	Kills a running background bash shell by its ID	No
MCPSearch	Searches for and loads MCP tools when tool search is enabled	No
NotebookEdit	Modifies Jupyter notebook cells	Yes
Read	Reads the contents of files	No
Skill	Executes a skill within the main conversation	Yes
Task	Runs a sub-agent to handle complex, multi-step tasks	No
TaskCreate	Creates a new task in the task list	No
TaskGet	Retrieves full details for a specific task	No
TaskList	Lists all tasks with their current status	No
TaskUpdate	Updates task status, dependencies, details, or deletes tasks	No
WebFetch	Fetches content from a specified URL	Yes
WebSearch	Performs web searches with domain filtering	Yes
Write	Creates or overwrites files	Yes
LSP	Code intelligence via language servers. Reports type errors and warnings automatically after file edits. Also supports navigation operations: jump to definitions, find references, get type info, list symbols, find implementations, trace call hierarchies. Requires a code intelligence plugin and its language server binary	No

Tools missing from official documentation (generated by Claude)

Tool	Description	Permission Required
EnterPlanMode	Requests permission to enter plan mode for complex tasks requiring exploration and design	No
TaskStop	Stops a running background task by its ID	No
TodoWrite	Manages task list entries	No
ToolSearch	Searches for and loads MCP tools when tool search is enabled	No

settings.local.json

{
  "permissions": {
    "allow": [],
    "deny": [
      "AskUserQuestion",
      "Bash",
      "Edit",
      "EnterPlanMode",
      "ExitPlanMode",
      "Glob",
      "Grep",
      "NotebookEdit",
      "Read",
      "Skill",
      "Task",
      "TaskCreate",
      "TaskGet",
      "TaskStop",
      "TaskList",
      "TaskOutput",
      "TaskUpdate",
      "TodoWrite",
      "ToolSearch",
      "WebFetch",
      "WebSearch",
      "Write"
    ]
  }
}