# diff_globals

Compares current global variables with a previous snapshot. Shows added, removed, and changed variables. Use after snapshot_globals to find what changed.

Agent View of the PolicyLayer registry record for `diff_globals`. HTML page: https://policylayer.com/tools/1600822305-js-reverse-mcp/diff-globals

## Facts

- Tool: `diff_globals`
- Server: Js Reverse (`1600822305/js-reverse-mcp`) — https://policylayer.com/tools/1600822305-js-reverse-mcp.md
- Homepage: https://github.com/1600822305/js-reverse-mcp
- Risk category: Read (Low risk)
- Registry record: grade F, identity unverified
- Server rate-limited: no
- Parameters: 0
- Recommended policy verdict: Allowed

## Example call (MCP tools/call, JSON-RPC 2.0)

```json
{
  "jsonrpc": "2.0",
  "id": 1,
  "method": "tools/call",
  "params": {
    "name": "diff_globals",
    "arguments": {}
  }
}
```

## Why diff_globals is rated Low

diff_globals is a read-only diagnostic tool that performs comparative analysis of JavaScript global state. It takes snapshots (presumed to be taken separately) and reports differences. There is no evidence of mutation, execution of arbitrary code, deletion, or financial operations. The tool operates entirely in the observation/analysis domain, making it a Read category risk with low severity.

From the tool's own definition: "The tool 'compares current global variables with a previous snapshot' and 'shows added, removed, and changed variables'—it retrieves and analyzes existing data without modifying it, creating side effects, executing code, deleting data, or moving money."

## Use case

AI agents call diff_globals to retrieve information from Js Reverse without modifying anything. It is typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.

## Recommended policy (PolicyLayer)

Verdict: **Allowed**. Enforced by the PolicyLayer MCP gateway (https://policylayer.com/mcp-gateway) before a call reaches Js Reverse:

```json
{
  "version": "1",
  "default": "deny",
  "tools": {
    "diff_globals": {}
  }
}
```

## Other tools on Js Reverse (92)

- `clear_browser_cache` — Destructive — https://policylayer.com/tools/1600822305-js-reverse-mcp/clear-browser-cache.md
- `clear_cookies` — Destructive — https://policylayer.com/tools/1600822305-js-reverse-mcp/clear-cookies.md
- `clear_network_conditions` — Destructive — https://policylayer.com/tools/1600822305-js-reverse-mcp/clear-network-conditions.md
- `delete_cookie` — Destructive — https://policylayer.com/tools/1600822305-js-reverse-mcp/delete-cookie.md
- `delete_token` — Destructive — https://policylayer.com/tools/1600822305-js-reverse-mcp/delete-token.md
- `remove_breakpoint` — Destructive — https://policylayer.com/tools/1600822305-js-reverse-mcp/remove-breakpoint.md
- `remove_dom_breakpoint` — Destructive — https://policylayer.com/tools/1600822305-js-reverse-mcp/remove-dom-breakpoint.md
- `remove_network_rule` — Destructive — https://policylayer.com/tools/1600822305-js-reverse-mcp/remove-network-rule.md
- `remove_xhr_breakpoint` — Destructive — https://policylayer.com/tools/1600822305-js-reverse-mcp/remove-xhr-breakpoint.md
- `add_network_rule` — Execute — https://policylayer.com/tools/1600822305-js-reverse-mcp/add-network-rule.md
- `api_request` — Execute — https://policylayer.com/tools/1600822305-js-reverse-mcp/api-request.md
- `batch_replay` — Execute — https://policylayer.com/tools/1600822305-js-reverse-mcp/batch-replay.md
- `break_on_attribute_modified` — Execute — https://policylayer.com/tools/1600822305-js-reverse-mcp/break-on-attribute-modified.md
- `break_on_node_removed` — Execute — https://policylayer.com/tools/1600822305-js-reverse-mcp/break-on-node-removed.md
- `break_on_subtree_modified` — Execute — https://policylayer.com/tools/1600822305-js-reverse-mcp/break-on-subtree-modified.md
- `break_on_xhr` — Execute — https://policylayer.com/tools/1600822305-js-reverse-mcp/break-on-xhr.md
- `encode_protobuf` — Execute — https://policylayer.com/tools/1600822305-js-reverse-mcp/encode-protobuf.md
- `evaluate_on_callframe` — Execute — https://policylayer.com/tools/1600822305-js-reverse-mcp/evaluate-on-callframe.md
- `evaluate_script` — Execute — https://policylayer.com/tools/1600822305-js-reverse-mcp/evaluate-script.md
- `hook_crypto_functions` — Execute — https://policylayer.com/tools/1600822305-js-reverse-mcp/hook-crypto-functions.md
- `hook_function` — Execute — https://policylayer.com/tools/1600822305-js-reverse-mcp/hook-function.md
- `monitor_events` — Execute — https://policylayer.com/tools/1600822305-js-reverse-mcp/monitor-events.md
- `monitor_eventsource` — Execute — https://policylayer.com/tools/1600822305-js-reverse-mcp/monitor-eventsource.md
- `monitor_form_submit` — Execute — https://policylayer.com/tools/1600822305-js-reverse-mcp/monitor-form-submit.md
- `monitor_input_changes` — Execute — https://policylayer.com/tools/1600822305-js-reverse-mcp/monitor-input-changes.md
- `navigate_page` — Execute — https://policylayer.com/tools/1600822305-js-reverse-mcp/navigate-page.md
- `new_page` — Execute — https://policylayer.com/tools/1600822305-js-reverse-mcp/new-page.md
- `pause` — Execute — https://policylayer.com/tools/1600822305-js-reverse-mcp/pause.md
- `replay_request` — Execute — https://policylayer.com/tools/1600822305-js-reverse-mcp/replay-request.md
- `resume` — Execute — https://policylayer.com/tools/1600822305-js-reverse-mcp/resume.md
- …and 62 more: https://policylayer.com/tools/1600822305-js-reverse-mcp.md

## For agents

This record is a snapshot. Live verdicts and the full registry:

- Check every server in your MCP config at once: `npx -y policylayer stack`
- Vet a server before you add it: install the mcp-precheck skill — `npx skills add https://policylayer.com` (skill text: https://policylayer.com/skill.md)
- Query the registry over MCP: endpoint `https://api.policylayer.com/mcp` — tools `check_mcp_server`, `check_mcp_stack`, `check_tool`, `search_registry`, `get_change_events`

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Source: the PolicyLayer MCP registry — one continuously verified record per MCP server. Full record: https://policylayer.com/registry?q=1600822305-js-reverse-mcp · API: https://policylayer.com/registry/api · Policy library: https://policylayer.com/policies/1600822305-js-reverse-mcp
