MapleStory MCP Server

get_union_ranking

Retrieve union power rankings for MapleStory characters by world, date, or specific name to track competitive standings.

Instructions

Retrieve union power rankings for a specific world or overall rankings

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": "get_union_ranking"
  }
}

Input Schema

Name	Required	Description
`worldName`	No	World name to get rankings for (optional, gets all worlds if not specified)
`characterName`	No	Specific character name to search for in rankings (optional)
`page`	No	Page number for pagination (1-based, optional, defaults to 1)
`date`	No	Date for rankings in YYYY-MM-DD format (optional, defaults to yesterday)

Schema Changelog

Changes observed during successful MCP inspections.

First observedv1.0.2Mar 14, 2026

TDQS

B3.1/5.0

Behavior2/5

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

With no annotations provided, the description carries full burden for behavioral disclosure. It mentions retrieval but doesn't describe what 'union power rankings' actually contain, how results are structured, whether there are rate limits, authentication requirements, or data freshness considerations. For a ranking tool with 4 parameters, this leaves significant behavioral gaps.

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?

The description is a single, efficient sentence that front-loads the core purpose. Every word earns its place - 'Retrieve' specifies the action, 'union power rankings' identifies the resource, and 'for a specific world or overall rankings' clarifies the scope options without redundancy.

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

Completeness3/5

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

For a read-only ranking tool with comprehensive schema documentation but no output schema, the description is minimally adequate. It identifies what's being retrieved but doesn't explain the ranking system, result format, or typical use cases. With no annotations and no output schema, more context about what 'union power rankings' represent would be helpful for the agent.

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 all parameters are well-documented in the schema itself. The description adds minimal value beyond the schema - it mentions 'specific world' which corresponds to worldName, and 'overall rankings' which implies no worldName, but doesn't provide additional semantic context about parameter interactions or ranking criteria.

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 clearly states the action ('Retrieve') and resource ('union power rankings'), and specifies the scope options ('for a specific world or overall rankings'). It doesn't explicitly differentiate from sibling tools like get_union_info or get_overall_ranking, but the focus on 'union power rankings' provides reasonable distinction.

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

Usage Guidelines2/5

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

No guidance is provided about when to use this tool versus alternatives like get_overall_ranking or get_union_info. The description mentions 'overall rankings' but doesn't clarify the relationship with the similarly named sibling tool get_overall_ranking, leaving the agent to guess about tool selection.

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

Deploy Server