MCP Tool
nova.external_tool_call
For extensions, external MCP sources, and bounded tool execution, an agent uses this public tool to handle the sensitive path "Discovery Trust-Gate". It keeps purpose, scope, user control, and sensitive data handling explicit.
Canonical reference for a public MCP tool name.
- Type
- MCP tool
- Family
- External MCP Transport Matrix & Cross-System Flows
- Effect
- sensitive
- Status
- Explained
- Path
- 46.11
Purpose
What this entry explains
What it does
nova.external_tool_call
An agent uses this tool to handle the sensitive path "Discovery Trust-Gate". It belongs to extensions, external MCP sources, and bounded tool execution; agents should combine it with current discovery, target awareness, and the visible result.
Use when
- Use this entry when an agent needs to handle the sensitive path "Discovery Trust-Gate" for extensions, external MCP sources, and bounded tool execution.
- Use it to understand the public tool name, its expected boundary, and the response signals to check.
- Use it before chaining follow-up tools so the next step is based on current evidence.
Reference Use
How agents should cite and apply this area
Examples are maintained at family level and use only public tool names or reference paths already present in the catalog.
Family example
A task in extensions, external MCP sources, and bounded tool execution can trigger powerful execution and therefore needs target, approval, and result check before the step.
The agent starts with nova.external_server_add, reads the current response or reference, and only then chooses the concrete next tool.
Current discovery, target, user control, warning signals, and result check come before execution.Contract
Inputs and important response fields
This page is a public reference. Agents and integrators should still read current MCP tool discovery before execution, because schemas can be gated by settings or version.
Inputs
No stable public input field is derived from the catalog source for this path. Read current MCP discovery before execution.
| Response field | Explanation |
|---|---|
user_approved | Response field named by the catalog source. Treat it as current evidence for the next decision. |
Safety
Boundary before execution
May touch sensitive data, permissions, credentials, identity, or external connection paths. Use only with explicit scope and visible user control.
Require explicit purpose and current context, avoid exposing secrets in prompts or logs, and stop when permission or identity state is unclear.
For humans, this entry marks the sensitive surface in extensions, external MCP sources, and bounded tool execution and keeps permission, credential, or external-connection handling explicit.
High-Impact Review
Execution boundary and recheck hints
Review category: Proxy/external connection
External targets, proxies, gateways, and transport paths may be used only with checked target, status, and approval.
False assumption: a reachable external tool is automatically part of the allowed Nova tool chain.
Target, transport status, import or connection approval, and expected data movement must be visible.
Do not silently add third-party tools; check current approval, target, and response status before use.
Recheck if the gateway, proxy, remote source, or target system changes or emits warnings.
Safety Axes
How this path can affect work
Axes are stable catalog signals for humans, agents, and LLM discovery. One path can carry several axes.
sensitive_data
Touches cookies, storage, clipboard, credentials, tokens, user content, identity, or private data.
Use only with bounded purpose and visible user control; do not guess, log, or forward sensitive values.external_connection
Uses proxy, external MCP gateways, network routes, third-party integrations, or import paths.
Check external target, transport status, and approval before use; do not silently chain third-party tools.user_confirmation
Requires visible confirmation, target review, approval, or deliberate user control.
Do not proceed until the required confirmation is visible or unambiguous in the current context.