# start_js_coverage Starts collecting JavaScript code coverage data. This tracks which parts of JavaScript code are executed. Agent View of the PolicyLayer registry record for `start_js_coverage`. HTML page: https://policylayer.com/tools/1600822305-js-reverse-mcp/start-js-coverage ## Facts - Tool: `start_js_coverage` - 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: Execute (High risk) - Registry record: grade F, identity unverified - Server rate-limited: no - Parameters: 0 - Recommended policy verdict: Rate-limited ## Example call (MCP tools/call, JSON-RPC 2.0) ```json { "jsonrpc": "2.0", "id": 1, "method": "tools/call", "params": { "name": "start_js_coverage", "arguments": {} } } ``` ## Why start_js_coverage is rated High Code coverage collection is an observational Execute action - it instruments and monitors JavaScript execution within a controlled browser context via Chrome DevTools Protocol. While it doesn't modify code or data, it does trigger monitoring mechanisms and alter browser behavior to collect execution data. This is less severe than Write (no state changes) but more than Read (active instrumentation). From the tool's own definition: "The tool 'starts collecting JavaScript code coverage data' which requires instrumenting and monitoring code execution within a browser context. Code coverage collection inherently involves executing and tracking JavaScript execution paths." ## Use case AI agents invoke start_js_coverage to trigger actions in Js Reverse. What it does depends on the arguments the agent supplies, and its effects often reach beyond the immediate call: builds kicked off, notifications sent, workflows started. ## Recommended policy (PolicyLayer) Verdict: **Rate-limited**. Enforced by the PolicyLayer MCP gateway (https://policylayer.com/mcp-gateway) before a call reaches Js Reverse: ```json { "version": "1", "default": "deny", "tools": { "start_js_coverage": { "limits": [ { "counter": "start_js_coverage_rate", "window": "minute", "max": 10, "scope": "grant" } ] } } } ``` ## 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` --- 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