PCSX2 MCP

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write_debug_register

Set the value of a PCSX2 debug register by specifying its category and index. Modify emulator debug registers directly for debugging and testing.

Instructions

Write a full-width PCSX2 debug register by category and index.

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": {
      "category": "<category>",
      "index": "<index>",
      "value": "<value>"
    },
    "name": "write_debug_register"
  }
}

Input Schema

Name	Required	Default
`index`	Yes
`value`	Yes
`target`	No	ee
`category`	Yes

Schema Changelog

Changes observed during successful MCP inspections.

First observedv0.1.0Jul 27, 2026

TDQS

C2.6/5.0

Behavior2/5

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

No annotations exist, and the description does not disclose effects or prerequisites. It merely states the action without detailing side effects, required state (e.g., emulation running), or error conditions.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Conciseness3/5

Is the description appropriately sized, front-loaded, and free of redundancy?

The description is a single sentence, but it is too brief to be informative. It sacrifices completeness for brevity.

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

Completeness2/5

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

With four parameters, no output schema, and no annotations, the description fails to provide necessary context for proper usage. Key aspects like target and value format are omitted.

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

Parameters2/5

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

Schema description coverage is 0%, and the description only mentions 'category and index' without explaining their meanings or constraints. The 'target' parameter is not described at all, and the value type remains ambiguous.

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 ('write'), the resource ('PCSX2 debug register'), and the method ('by category and index'). However, it does not differentiate from sibling 'write_register' or explain what 'full-width' means.

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 on when to use this tool versus alternatives like 'write_register' or 'get_debug_registers'. The agent is left without context for selection.

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