# evaluate_on_callframe Evaluates a JavaScript expression in the context of a specific call frame while paused. This allows you to inspect variables and execute code in the paused scope. Agent View of the PolicyLayer registry record for `evaluate_on_callframe`. HTML page: https://policylayer.com/tools/1600822305-js-reverse-mcp/evaluate-on-callframe ## Facts - Tool: `evaluate_on_callframe` - 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": "evaluate_on_callframe", "arguments": {} } } ``` ## Why evaluate_on_callframe is rated High Evaluating and executing arbitrary JavaScript expressions in a browser context is a code execution action. While the scope is limited to debugging/paused states, this still permits running untrusted code with full access to the page's DOM, cookies, storage, and network capabilities. The high severity reflects potential for data theft, session hijacking, or malicious actions against web applications being debugged. From the tool's own definition: "Tool description states it 'Evaluates a JavaScript expression' and 'execute[s] code in the paused scope.' The server enables 'control [of] browsers' via Chrome DevTools Protocol. These capabilities allow arbitrary code execution within a browser context." ## Use case AI agents invoke evaluate_on_callframe 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": { "evaluate_on_callframe": { "limits": [ { "counter": "evaluate_on_callframe_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_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 - `set_breakpoint` — Execute — https://policylayer.com/tools/1600822305-js-reverse-mcp/set-breakpoint.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