ares-mcp

ares_cross_company_persons

Detect individuals holding statutory roles in multiple Czech companies from IČOs. Returns structured cross-reference and optional graph to reveal hidden links for due diligence.

Instructions

Given a list of Czech IČOs, find natural persons (and legal entities) who hold active statutory roles in two or more of them. Returns a structured cross-reference plus an optional Mermaid graph for visualization. Useful for due diligence (holding-group mapping, undisclosed beneficial connections, nominee director detection on a small known set).

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": {
      "icos": "<icos>"
    },
    "name": "ares_cross_company_persons"
  }
}

Input Schema

Name	Required	Description
`icos`	Yes	List of 2–50 Czech IČOs to cross-reference. Each will be validated and looked up in the Public Register (VR).
`emitMermaid`	No	If true, also include a Mermaid `graph LR` string that MCP clients (e.g. Claude) can render as a visual person→companies diagram.
`includeHistorical`	No	If true, include former members (those with `datumVymazu` set). Useful for nominee director detection and tracking director musical chairs. Default false = active members only.

Schema Changelog

Changes observed during successful MCP inspections.

First observedv0.1.2Aug 7, 2026

TDQS

A4/5.0

Behavior3/5

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

No annotations are provided, so the description carries the full burden. It discloses the core behavior (filtering to active roles, cross-referencing two or more) and the output (structured cross-reference plus optional Mermaid graph). However, it doesn't mention validation of IČOs, potential errors, rate limits, or that it queries the Public Register (only implied in schema). This is a moderate disclosure for a read-only lookup tool.

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 exactly two sentences, with the primary purpose front-loaded and no redundant information. Every word contributes to understanding what the tool does and when to use it.

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 tool with three parameters, no output schema, and no annotations, the description adequately covers its complexity. It states what is returned (cross-reference and Mermaid graph) and provides context (due diligence scenarios). It could specify the structure of the cross-reference in more detail, but the current description is sufficient for typical use.

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 three parameters (icos, emitMermaid, includeHistorical) have detailed descriptions. The tool description adds minimal parameter-specific detail beyond the schema, but it does clarify the purpose of the cross-reference and the optional visualization. This meets the baseline for high schema coverage.

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 explicitly states the tool's function: given a list of Czech IČOs, find natural persons/legal entities holding active statutory roles in two or more of them. It uses a specific verb ('find') and resource, and clearly distinguishes from sibling tools like ares_get_statutory_bodies by emphasizing cross-company overlap.

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 provides clear use cases ('due diligence, holding-group mapping, undisclosed beneficial connections, nominee director detection') and implies it's for a 'small known set', offering practical guidance on when to apply this tool. It doesn't explicitly name alternative tools or state when not to use it, but the use-case framing is strong.

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

Deploy Server