emptysock-mcp

physics_body_state

Retrieve a physics body's current position, velocity, and angular velocity using its entity ID to track its motion.

Instructions

Return the current position, velocity, and angular velocity of a physics body by entity ID.

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": {
      "entityId": "<entityId>"
    },
    "name": "physics_body_state"
  }
}

Input Schema

Name	Required	Description	Default
`entityId`	Yes

Schema Changelog

Changes observed during successful MCP inspections.

First observedv0.1.0Sep 10, 2026

TDQS

A3.5/5.0

Behavior3/5

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

With no annotations, the description carries the burden of behavioral disclosure. It clearly indicates a read-style operation by saying 'Return', and it names the returned fields, but it does not mention failure behavior, coordinate units, or whether the entity must already have a physics body. This is adequate but incomplete.

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, well-structured sentence with no filler. It front-loads the action and output, then states the input scope concisely.

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 one-parameter getter with no output schema, the description covers the essential input and output. It lacks details about error cases, units, or coordinate systems, but the tool's complexity is low and the description is largely sufficient for an agent to invoke it correctly.

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 must compensate. It only repeats the parameter name ('entityId') through the phrase 'by entity ID' and adds no detail about what IDs are valid, what entity types are expected, or how missing or invalid IDs are handled. The sole parameter is self-explanatory, but the description adds little semantic value.

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 uses a specific verb ('Return') and a clear resource ('physics body'), and names the exact data returned: position, velocity, and angular velocity. It is sufficiently distinct from sibling tools like physics_raycast_2d/3d and navmesh tools, which serve different purposes.

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?

There is no guidance about when to choose this tool over alternatives, nor any mention of prerequisites or exclusions. The phrase 'by entity ID' implies an input requirement, but the description does not explain when this tool should be used versus scene_entity_info or other physics tools.

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