# call_webmcp_tool

Invoke a WebMCP tool on a connected origin. The tool is executed in the browser page context via page.evaluate(). Args are validated for suspicious patterns and results are scanned for anomalies. Use list_webmcp_tools to see available tools first.

Agent View of the PolicyLayer registry record for `call_webmcp_tool`. HTML page: https://policylayer.com/tools/io-github-homenshum-nodebench/call-webmcp-tool

## Facts

- Tool: `call_webmcp_tool`
- Server: Nodebench (`nodebench-mcp`) — https://policylayer.com/tools/io-github-homenshum-nodebench.md
- Install: `npx -y nodebench-mcp`
- Homepage: https://github.com/HomenShum/nodebench-ai
- 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": "call_webmcp_tool",
    "arguments": {}
  }
}
```

## Why call_webmcp_tool is rated High

This tool invokes arbitrary WebMCP tools in a browser context using page.evaluate(), which can execute JavaScript code and trigger external operations. While the description mentions argument validation and result scanning for anomalies, these are mitigations rather than categorical constraints.

From the tool's own definition: "tool is executed in the browser page context via page.evaluate(); invoke, execute, and browser actions directly indicate Execute category"

## Use case

AI agents invoke call_webmcp_tool to trigger actions in Nodebench. 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 Nodebench:

```json
{
  "version": "1",
  "default": "deny",
  "tools": {
    "call_webmcp_tool": {
      "limits": [
        {
          "counter": "call_webmcp_tool_rate",
          "window": "minute",
          "max": 10,
          "scope": "grant"
        }
      ]
    }
  }
}
```

## Other tools on Nodebench (823)

- `abandon_cycle` — Destructive — https://policylayer.com/tools/io-github-homenshum-nodebench/abandon-cycle.md
- `archiveDocument` — Destructive — https://policylayer.com/tools/io-github-homenshum-nodebench/archivedocument.md
- `cleanup_stale_runs` — Destructive — https://policylayer.com/tools/io-github-homenshum-nodebench/cleanup-stale-runs.md
- `deeptrace_revoke_passport` — Destructive — https://policylayer.com/tools/io-github-homenshum-nodebench/deeptrace-revoke-passport.md
- `delete_learning` — Destructive — https://policylayer.com/tools/io-github-homenshum-nodebench/delete-learning.md
- `delete_sandbox_policy` — Destructive — https://policylayer.com/tools/io-github-homenshum-nodebench/delete-sandbox-policy.md
- `deleteAgentMemory` — Destructive — https://policylayer.com/tools/io-github-homenshum-nodebench/deleteagentmemory.md
- `removeDocumentFromFolder` — Destructive — https://policylayer.com/tools/io-github-homenshum-nodebench/removedocumentfromfolder.md
- `share_revoke_packet_link` — Destructive — https://policylayer.com/tools/io-github-homenshum-nodebench/share-revoke-packet-link.md
- `unload_toolset` — Destructive — https://policylayer.com/tools/io-github-homenshum-nodebench/unload-toolset.md
- `benchmark_models` — Execute — https://policylayer.com/tools/io-github-homenshum-nodebench/benchmark-models.md
- `bootstrap_parallel_agents` — Execute — https://policylayer.com/tools/io-github-homenshum-nodebench/bootstrap-parallel-agents.md
- `build_banking_packet` — Execute — https://policylayer.com/tools/io-github-homenshum-nodebench/build-banking-packet.md
- `build_company_profile_starter` — Execute — https://policylayer.com/tools/io-github-homenshum-nodebench/build-company-profile-starter.md
- `build_founder_operating_model` — Execute — https://policylayer.com/tools/io-github-homenshum-nodebench/build-founder-operating-model.md
- `build_research_digest` — Execute — https://policylayer.com/tools/io-github-homenshum-nodebench/build-research-digest.md
- `build_shared_context_subscription` — Execute — https://policylayer.com/tools/io-github-homenshum-nodebench/build-shared-context-subscription.md
- `build_shared_context_subscription_manifest` — Execute — https://policylayer.com/tools/io-github-homenshum-nodebench/build-shared-context-subscription-manifest.md
- `build_submission_export` — Execute — https://policylayer.com/tools/io-github-homenshum-nodebench/build-submission-export.md
- `build_temporal_graph` — Execute — https://policylayer.com/tools/io-github-homenshum-nodebench/build-temporal-graph.md
- `burst_capture` — Execute — https://policylayer.com/tools/io-github-homenshum-nodebench/burst-capture.md
- `call_driver_tool` — Execute — https://policylayer.com/tools/io-github-homenshum-nodebench/call-driver-tool.md
- `call_llm` — Execute — https://policylayer.com/tools/io-github-homenshum-nodebench/call-llm.md
- `call_openclaw_skill` — Execute — https://policylayer.com/tools/io-github-homenshum-nodebench/call-openclaw-skill.md
- `capture_surface_stats` — Execute — https://policylayer.com/tools/io-github-homenshum-nodebench/capture-surface-stats.md
- `capture_ui_screenshot` — Execute — https://policylayer.com/tools/io-github-homenshum-nodebench/capture-ui-screenshot.md
- `compile_decision_packet` — Execute — https://policylayer.com/tools/io-github-homenshum-nodebench/compile-decision-packet.md
- `compile_scenarios` — Execute — https://policylayer.com/tools/io-github-homenshum-nodebench/compile-scenarios.md
- `compile_tension_model` — Execute — https://policylayer.com/tools/io-github-homenshum-nodebench/compile-tension-model.md
- `compute_ssim_analysis` — Execute — https://policylayer.com/tools/io-github-homenshum-nodebench/compute-ssim-analysis.md
- …and 793 more: https://policylayer.com/tools/io-github-homenshum-nodebench.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=io-github-homenshum-nodebench · API: https://policylayer.com/registry/api · Policy library: https://policylayer.com/policies/io-github-homenshum-nodebench