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scarletfantasy

pix-mcp

pix_run_debug_layer

Read-onlyIdempotent

Replay a captured frame with the D3D12 debug layer enabled to identify and surface validation errors.

Instructions

Replay the capture with the D3D12 debug layer on, to surface validation errors.

Input Schema

TableJSON Schema
NameRequiredDescriptionDefault
capture_idYes
timeout_secondsNo

Output Schema

TableJSON Schema
NameRequiredDescriptionDefault

No arguments

Schema Changelog

Changes observed during successful MCP inspections.

  1. First observedv0.1.0

TDQS

A3.9/5.0
Behavior4/5

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

Annotations already mark the tool as readOnly, idempotent, and non-destructive, and the description does not contradict them. The description adds behavioral context beyond annotations: it replays the capture and enables the D3D12 debug layer, which implies slower execution and explains why a timeout_seconds parameter may be needed.

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 a single sentence, front-loaded with the action, with no filler or redundant detail. Every word contributes to understanding what the tool does.

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 two-parameter tool with an output schema and safety annotations, the description adequately explains what it does and why. A note about the optional timeout being useful because debug-layer replay can be slow would round it out, but nothing essential for invoking the tool is missing.

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%, so the description carries the full burden, but it names no parameters. capture_id and timeout_seconds are inferable from their names and the general description, yet their exact semantics, especially the meaning and default behavior of timeout_seconds, are not explained.

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 opens with a specific verb, 'Replay', and names the exact resource: the capture, with the D3D12 debug layer enabled. It also states the outcome ('to surface validation errors'), which distinguishes it from ordinary playback tools like pix_perform_playback.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Usage Guidelines3/5

Does the description explain when to use this tool, when not to, or what alternatives exist?

The stated purpose, 'to surface validation errors', gives a clear context for when this tool is useful. However, it does not explicitly mention when not to use it or point to alternative replay/playback tools, so usage guidance remains implied rather than explicit.

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