# call_tool

Run ANY Hermoso tool by name — including the paid-campaign, analytics and channel-admin tools that are not in this session\

Agent View of the PolicyLayer registry record for `call_tool`. HTML page: https://policylayer.com/tools/hermoso/call-tool

## Facts

- Tool: `call_tool`
- Server: Hermoso (`https://app.hermoso.ai/mcp`) — https://policylayer.com/tools/hermoso.md
- Homepage: git+https://github.com/hermoso-ai/hermoso.git
- Risk category: Execute (High risk)
- Registry record: grade D, identity unverified
- Server auth posture: gated
- Server CORS policy: *
- 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_tool",
    "arguments": {}
  }
}
```

## Why call_tool is rated High

call_tool triggers real processes with real consequences. An agent gone sideways doesn't fire it once. It starts dozens of builds, sends mass notifications, or burns through compute before anyone looks up.

Risk signals: Admin/system-level operation

## Use case

AI agents invoke call_tool to trigger actions in Hermoso. 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 Hermoso:

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

## Other tools on Hermoso (895)

- `answer_google_business_question` — Destructive — https://policylayer.com/tools/hermoso/answer-google-business-question.md
- `apple_ads_change_history` — Destructive — https://policylayer.com/tools/hermoso/apple-ads-change-history.md
- `associate_linkedin_conversion_campaigns` — Destructive — https://policylayer.com/tools/hermoso/associate-linkedin-conversion-campaigns.md
- `cancel_openai_ads_audience_operation` — Destructive — https://policylayer.com/tools/hermoso/cancel-openai-ads-audience-operation.md
- `cancel_scheduled` — Destructive — https://policylayer.com/tools/hermoso/cancel-scheduled.md
- `cancel_stripe_subscription` — Destructive — https://policylayer.com/tools/hermoso/cancel-stripe-subscription.md
- `clear_sheet_range` — Destructive — https://policylayer.com/tools/hermoso/clear-sheet-range.md
- `create_analytics_custom_dimension` — Destructive — https://policylayer.com/tools/hermoso/create-analytics-custom-dimension.md
- `create_openai_ads_campaign` — Destructive — https://policylayer.com/tools/hermoso/create-openai-ads-campaign.md
- `delete_analytics_key_event` — Destructive — https://policylayer.com/tools/hermoso/delete-analytics-key-event.md
- `delete_apple_ads_object` — Destructive — https://policylayer.com/tools/hermoso/delete-apple-ads-object.md
- `delete_bluesky_post` — Destructive — https://policylayer.com/tools/hermoso/delete-bluesky-post.md
- `delete_brand` — Destructive — https://policylayer.com/tools/hermoso/delete-brand.md
- `delete_creator` — Destructive — https://policylayer.com/tools/hermoso/delete-creator.md
- `delete_dm_automation` — Destructive — https://policylayer.com/tools/hermoso/delete-dm-automation.md
- `delete_drive_file` — Destructive — https://policylayer.com/tools/hermoso/delete-drive-file.md
- `delete_google_ads_object` — Destructive — https://policylayer.com/tools/hermoso/delete-google-ads-object.md
- `delete_google_business_post` — Destructive — https://policylayer.com/tools/hermoso/delete-google-business-post.md
- `delete_instagram_dm_automation` — Destructive — https://policylayer.com/tools/hermoso/delete-instagram-dm-automation.md
- `delete_linkedin_ads_object` — Destructive — https://policylayer.com/tools/hermoso/delete-linkedin-ads-object.md
- `delete_linkedin_comment` — Destructive — https://policylayer.com/tools/hermoso/delete-linkedin-comment.md
- `delete_linkedin_lead_subscription` — Destructive — https://policylayer.com/tools/hermoso/delete-linkedin-lead-subscription.md
- `delete_merchant_data_source` — Destructive — https://policylayer.com/tools/hermoso/delete-merchant-data-source.md
- `delete_merchant_product` — Destructive — https://policylayer.com/tools/hermoso/delete-merchant-product.md
- `delete_messenger_marketing_campaign` — Destructive — https://policylayer.com/tools/hermoso/delete-messenger-marketing-campaign.md
- `delete_meta_audience` — Destructive — https://policylayer.com/tools/hermoso/delete-meta-audience.md
- `delete_meta_catalog` — Destructive — https://policylayer.com/tools/hermoso/delete-meta-catalog.md
- `delete_meta_object` — Destructive — https://policylayer.com/tools/hermoso/delete-meta-object.md
- `delete_microsoft_ads_object` — Destructive — https://policylayer.com/tools/hermoso/delete-microsoft-ads-object.md
- `delete_microsoft_merchant_product` — Destructive — https://policylayer.com/tools/hermoso/delete-microsoft-merchant-product.md
- …and 865 more: https://policylayer.com/tools/hermoso.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=hermoso · API: https://policylayer.com/registry/api · Policy library: https://policylayer.com/policies/hermoso