llm-chess-mcp

Create Chess Game

create_game

Start a new chess game and obtain its unique game ID. Optionally provide a FEN to begin from a custom position.

Instructions

Create a new chess game and return its game_id. The server is the authoritative source of board state — never track the board yourself. Optionally pass a FEN to start from a custom position.

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": "create_game"
  }
}

Input Schema

Name	Required	Description	Default
`fen`	No

Output Schema

Name	Required	Description	Default
`game_id`	Yes
`revision`	Yes

Schema Changelog

Changes observed during successful MCP inspections.

First observedv0.3.1Aug 21, 2026

TDQS

A4.5/5.0

Behavior4/5

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

Annotations (readOnlyHint=false) already indicate a write operation, but the description adds the critical behavioral directive to treat the server as the source of truth and avoid local board tracking. It also discloses the return of game_id. This goes beyond what annotations provide.

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 two sentences and front-loaded with the primary action. Each sentence adds value: the core function, the state-tracking warning, and the optional parameter explanation. No wasted words.

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 create tool with one optional parameter and an existing output schema, the description covers the essential aspects: what it does, return value, usage caution, and parameter semantics. It does not mention error behavior or prerequisites, but these are not critical for this tool's complexity.

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

Parameters5/5

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

The schema has 0% coverage for the 'fen' parameter, but the description clearly explains that it is optional and used to start from a custom FEN position. This fully compensates for the missing schema description.

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 starts with a specific verb+resource pair ('Create a new chess game') and explicitly states the return value (game_id), making the tool's purpose unambiguous. It also clearly distinguishes from siblings like delete_game and game_import_pgn.

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 gives clear usage context: the server is authoritative and one should never track the board locally, which implies how to use this with other game-state tools. It also notes the optional FEN for custom positions but does not explicitly exclude alternatives like game_import_pgn.

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

Deploy Server