PCSX2 MCP

by snowyegret23

Overview Schema Source Related Servers Discussions Admin

Python

Local

start_trace

Initiate background tracing of registers and memory in PCSX2, with optional JSONL output for debugging.

Instructions

Start background register/memory tracing, optionally writing JSONL records.

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": {
      "trace_id": "<trace_id>"
    },
    "name": "start_trace"
  }
}

Input Schema

Name	Required	Default
`target`	No	ee
`trace_id`	Yes
`registers`	No
`interval_ms`	No
`max_samples`	No
`output_path`	No
`memory_ranges`	No

Schema Changelog

Changes observed during successful MCP inspections.

First observedv0.1.0Jul 27, 2026

TDQS

C2.5/5.0

Behavior2/5

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

The description mentions 'background' tracing, hinting at non-blocking behavior, but fails to disclose side effects (e.g., does it overwrite existing traces?), requirements, or how to stop tracing. With no annotations, this is insufficient.

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, making it concise, but it is under-specified for a tool with 7 parameters. It sacrifices clarity for brevity.

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

Completeness1/5

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

Given the tool's complexity (7 parameters, no annotations, no output schema), the description is grossly incomplete. It omits parameter details, return behavior, side effects, and operational context.

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?

With 0% schema description coverage, the description must compensate, but it only vaguely references 'JSONL records' without linking to specific parameters (e.g., output_path). Most parameters remain unexplained.

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 it starts background register/memory tracing with optional JSONL output. It implicitly distinguishes from sibling tools like 'sample_trace' (one-time sample) and 'list_traces' (listing), but lacks explicit differentiation.

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 on when to use this vs alternatives (e.g., sample_trace). No prerequisites or context provided, leaving the agent to guess when this tool is appropriate.

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