vessel-traffic-mcp

Port Calls

port_calls

Read-onlyIdempotent

Retrieve recent port-call events for a vessel by MMSI or IMO, or for a port by UN/LOCODE. Requires at least one filter.

Instructions

Return recent port-call events for a vessel by MMSI/IMO or for a UN/LOCODE port. Requires at least one filter.

Tool call template

This tool declares no required parameters. Add optional parameters from the input schema as needed.

{
  "id": 1,
  "jsonrpc": "2.0",
  "method": "tools/call",
  "params": {
    "arguments": {},
    "name": "port_calls"
  }
}

Input Schema

Name	Required	Description	Default
`mmsi`	No
`imo`	No
`portUnlocode`	No
`limit`	No
`provider`	No
`credentialProfile`	No
`oneTimeCredential`	No
`fallbackPolicy`	No
`coverageHint`	No

Schema Changelog

Changes observed during successful MCP inspections.

First observedv0.1.0May 27, 2026

TDQS

B3.1/5.0

Behavior2/5

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

Annotations already indicate readOnly and idempotent behavior, but the description adds no extra context about the return format, pagination, or what 'recent' means.

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

Conciseness3/5

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

The description is very short and front-loaded, but may be too concise given the tool's complexity, omitting important parameter context.

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

Completeness2/5

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

Given 9 parameters, no output schema, and nested objects, the description provides insufficient detail for correct invocation.

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?

With 0% schema description coverage, the description explains only mmsi, imo, and portUnlocode as filters, ignoring the 6 other parameters like credentialProfile and fallbackPolicy.

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 clearly states the tool returns recent port-call events for a vessel by MMSI/IMO or for a UN/LOCODE port, which distinguishes it from sibling tools like vessel_position or vessel_schedule.

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

Usage Guidelines3/5

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

The description mentions 'Requires at least one filter' but does not elaborate on when to use this tool over alternatives or specify exclusions.

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

Deploy Server