llm-chess-mcp

Evaluate Chess Moves

move_evaluate

Read-onlyIdempotent

Evaluate chess moves with Stockfish. Returns score, centipawn loss, and quality classification for each move, without altering the game state.

Instructions

Evaluate one or more moves with Stockfish without mutating the game. Pass a single move string or an array of moves to compare. Returns, for each move, the score after the move (from the mover's perspective), cpLoss vs the best move, and a classification (best/excellent/good/inaccuracy/mistake/blunder).

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": {
      "game_id": "<game_id>",
      "move": "<move>"
    },
    "name": "move_evaluate"
  }
}

Input Schema

Name	Required	Description	Default
`move`	Yes
`depth`	No
`game_id`	Yes

Output Schema

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

Schema Changelog

Changes observed during successful MCP inspections.

First observedv0.3.1Aug 21, 2026

TDQS

A4.2/5.0

Behavior4/5

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

Annotations include readOnlyHint=true and idempotentHint=true, and the description explicitly states 'without mutating the game,' reinforcing that. It also adds value by describing the output (score, cpLoss, classification) and the engine (Stockfish), which are not required but provide useful behavioral context.

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 concise—three sentences—and front-loaded with the core purpose and non-mutation guarantee. Every sentence adds meaning without redundancy.

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?

An output schema is present, so detailed return field explanations are unnecessary. The description covers the primary purpose, input flexibility, and key output categories, making it adequate for most usage scenarios. Minor omissions (e.g., depth semantics) are acceptable given the schema's constraints.

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 coverage is 0% and the description partially compensates by explaining the 'move' parameter format (string or array). However, it does not clarify the 'depth' or 'game_id' parameters beyond what the schema already provides, leaving incomplete semantic 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 clearly states the tool evaluates moves using Stockfish, specifying the action (evaluate), resource (moves), and context (without mutating the game). It distinguishes itself from sibling tools like game_play_move (which mutates) and game_legal_moves (which lists legal moves).

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 implies its use for analysis rather than gameplay via 'without mutating the game' and mentions comparing moves, which gives context. However, it does not explicitly name alternative tools or provide exclusion criteria, so it falls short of a perfect score.

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

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