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キー押下(保持)

dx12_key_down

Simulate holding a key down for continuous input. Use with a key name or VK code to test press-and-hold behaviors in game playback.

Instructions

キーを押した状態にする(key_up を呼ぶまで保持)。次フレーム以降の Lua input:isKeyDown / keyDown() が true になる。横移動など「押しっぱなし」の挙動確認に。key は VK 整数 or 名前("W","D","SPACE","UP" 等)。Playing 中に使う(isAsyncKeyDown 系には効かない)。

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": {
      "key": "<key>"
    },
    "name": "dx12_key_down"
  }
}

Input Schema

Name	Required	Description	Default
`key`	Yes	VK コード(int)かキー名("W","SPACE","UP","F1" 等)

Output Schema

Name	Required	Description	Default
`result`	No	エンジンからの生の結果。実際の形は各ツールの説明 / dx12_describe_components を参照。text にも同内容を JSON 文字列で格納。

Schema Changelog

Changes observed during successful MCP inspections.

First observedv0.1.0Jul 8, 2026

TDQS

A4.4/5.0

Behavior4/5

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

With only openWorldHint annotation, the description adds key behavioral traits: it holds the key, affects Lua input:isKeyDown from next frame, works only in Playing mode, and does not affect isAsyncKeyDown. However, it omits details like multiple calls behavior or side effects.

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 with 4 sentences, each serving a purpose: action, effect, use case, and parameter details. No redundant or unnecessary text.

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?

Given the tool's simplicity (1 param, output schema exists), the description covers purpose, usage constraints, and parameter format. It could mention the return value or that it's for input simulation, but it's mostly complete.

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

Parameters4/5

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

The input schema already fully describes the parameter with 100% coverage. The description adds examples ('W', 'D', 'SPACE', 'UP') and clarifies it accepts both VK integer and name, enhancing usability.

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 puts a key in a pressed state and holds it until key_up is called, which is distinct from key_press (tap) and key_up (release). It also specifies it's for held-down behavior like horizontal movement, making it easy to differentiate from siblings.

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 says 'Use while Playing' and that it does not affect isAsyncKeyDown series, providing context. It implies key_up is needed to release, but does not explicitly state when not to use it or suggest alternatives like key_press for taps.

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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