netdiag-mcp

tcp_port_check

Verify whether a TCP port is open on a remote host by attempting a plain socket connection. Helps identify connectivity issues without port scanning.

Instructions

Check whether a TCP port is open (plain socket connect, no port scanning).

Tool call template

Replace each placeholder with a value matching the input schema. Only required parameters are included; add optional parameters as needed.

{
  "id": 1,
  "jsonrpc": "2.0",
  "method": "tools/call",
  "params": {
    "arguments": {
      "host": "<host>",
      "port": "<port>"
    },
    "name": "tcp_port_check"
  }
}

Input Schema

Name	Required	Description	Default
`host`	Yes
`port`	Yes
`timeout`	No

Output Schema

Name	Required	Description	Default
`result`	Yes

Schema Changelog

Changes observed during successful MCP inspections.

First observedv0.1.0Aug 30, 2026

TDQS

A3.9/5.0

Behavior3/5

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

With no annotations provided, the description carries the full burden for behavioral disclosure. It does reveal the mechanism ('plain socket connect') and expressly rules out scanning, but it does not mention timeout behavior, error/closed-port semantics, or other operational details that could affect the agent's expectation.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Conciseness5/5

Is the description appropriately sized, front-loaded, and free of redundancy?

A single sentence with no wasted words. The core action is front-loaded, and the clarifying exclusion is concise and useful.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Completeness4/5

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

For a simple single-port connectivity check, the description is nearly sufficient, especially because an output schema exists. It lacks explicit timeout semantics and host resolution behavior, but these are relatively minor gaps for this straightforward tool.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Parameters2/5

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema description coverage is 0%, and the description does not explain host, port, or timeout. The phrase 'TCP port' clarifies that port refers to a TCP port number, but no units for timeout, host format, or range constraints are provided, so the description adds little beyond the schema.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Purpose5/5

Does the description clearly state what the tool does and how it differs from similar tools?

The description uses a specific verb ('check'), a clear resource ('TCP port'), and a defined method ('plain socket connect'), making the tool's purpose immediately understandable. The explicit exclusion 'no port scanning' helps distinguish it from broader network-scanning tools and sibling diagnostics.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Usage Guidelines4/5

Does the description explain when to use this tool, when not to, or what alternatives exist?

The description clearly indicates the tool is for checking whether a single TCP port is open, which gives strong contextual guidance for when to select it. It also explicitly excludes port scanning, but it does not name sibling tools or state when to prefer alternatives like http_check or ping_host.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.

Deploy Server