VesselAPI MCP Server

by vessel-api

Overview Schema Source Related Servers Discussions Admin

TypeScript

list_emissions

Retrieve EU MRV annual emissions reports for ships calling at EU and EEA ports, with an optional reporting-year filter.

Instructions

List EU MRV annual emissions reports (ships calling at EU and EEA ports), with an optional reporting-year 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": "list_emissions"
  }
}

Input Schema

Name	Required	Description
`limit`	No	Results per page, 1 to 50. Defaults to 20.
`period`	No	Reporting year filter (e.g. 2024)
`nextToken`	No	Pagination token from previous response

Schema Changelog

Changes observed during successful MCP inspections.

Changed1 schema field changedv2.2.0Oct 30, 2026
- removedInput schema / additionalProperties
```
Removed value: -false
```
Changed4 schema fields changedv2.0.0Aug 20, 2026
- changedInput schema / properties / limit / description
```
Previous value: -"Max results per page"New value: +"Results per page, 1 to 50. Defaults to 20."
```
- addedInput schema / properties / limit / maximum
```
Added value: +50
```
- addedInput schema / properties / limit / minimum
```
Added value: +1
```
- changedInput schema / properties / limit / type
```
Previous value: -"number"New value: +"integer"
```
Addedv1.3.0May 6, 2026

TDQS

A3.6/5.0

Behavior3/5

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

No annotations are provided, so the description carries the behavioral burden. 'List' signals a read-only operation and the EU MRV/EEA scope adds useful domain context, but pagination behavior, output fields, and rate limits are not described.

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?

It is a single, front-loaded sentence with no wasted words. The core resource and optional filter are stated immediately.

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 three-parameter list endpoint with full schema coverage, the description gives enough scope to call it correctly. It lacks output-shape and pagination details, but those are partly covered by the schema and the tool's simplicity limits the gap.

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

Parameters3/5

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

Schema description coverage is 100%, so the schema already documents limit, period, and nextToken. The description only restates the optional reporting-year filter, consistent with the period parameter, and adds no syntax or format detail beyond the schema.

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

Purpose4/5

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

The description gives a specific verb and resource: 'List EU MRV annual emissions reports', and adds the scope of ships calling at EU and EEA ports. It is clear what the tool returns, but it does not explicitly distinguish itself from the sibling get_vessel_emissions.

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 implies when to use it by naming the EU MRV annual emissions dataset and an optional reporting-year filter. However, it gives no explicit when-not-to-use guidance or comparison to get_vessel_emissions, leaving the agent to infer the choice.

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