# nb_start_agent

Start a new agent conversation with an optional initial message.

Agent View of the PolicyLayer registry record for `nb_start_agent`. HTML page: https://policylayer.com/tools/io-github-homenshum-nodebench/nb-start-agent

## Facts

- Tool: `nb_start_agent`
- 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": "nb_start_agent",
    "arguments": {}
  }
}
```

## Why nb_start_agent is rated High

Starting an agent is an Execute action because it triggers an external computational process whose side effects are not predetermined and depend on arguments (the initial message). While not as severe as running arbitrary shell commands, it initiates autonomous decision-making that could perform reads, writes, or other operations.

From the tool's own definition: "Tool name 'nb_start_agent' and description 'Start a new agent conversation with an optional initial message' indicates launching an autonomous agent process."

## Use case

AI agents invoke nb_start_agent 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": {
    "nb_start_agent": {
      "limits": [
        {
          "counter": "nb_start_agent_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
- `call_webmcp_tool` — Execute — https://policylayer.com/tools/io-github-homenshum-nodebench/call-webmcp-tool.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
- …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