> ## Documentation Index
> Fetch the complete documentation index at: https://docs.tryvoss.dev/llms.txt
> Use this file to discover all available pages before exploring further.

# Tool registry

> The controlled tool surface Voss exposes to the harness agent.

The harness exposes a local tool registry. Each tool is classified as read-only or mutating so permission modes can make reliable decisions.

Each entry is a **capability** in the broader registry — it also declares a group, network usage, scope requirements, and audit behavior. [Roles](/orchestration/team-config) grant capabilities by group, and the full normalized schema lives in the [Capabilities reference](/reference/capabilities).

## Tool classes

| Tool          | Class     | Purpose                                                    |
| ------------- | --------- | ---------------------------------------------------------- |
| `fs_read`     | Read-only | Read files and directory summaries                         |
| `fs_glob`     | Read-only | Find files by glob pattern                                 |
| `fs_grep`     | Read-only | Search file contents                                       |
| `git_status`  | Read-only | Inspect working tree state                                 |
| `git_diff`    | Read-only | Inspect diffs                                              |
| `voss_check`  | Read-only | Run Voss checks                                            |
| `code_recall` | Read-only | Search code and project memory for concept-level questions |
| `fs_write`    | Mutating  | Write a file                                               |
| `fs_edit`     | Mutating  | Patch an existing file                                     |
| `shell_run`   | Mutating  | Run an allowlisted shell command                           |

## Diff previews

File write tools produce a diff preview before permission decisions. This keeps risky changes inspectable before approval.

## View tools locally

```bash theme={"theme":"github-dark"}
voss tools
```

The command shows registered tools and whether each one mutates state.

<Tip>
  Tool mutability is data in the registry. Voss should not infer safety from a tool name alone. Inspect the full capability surface with `voss capabilities list` and `voss capabilities inspect <name>`.
</Tip>