Skip to main content
Glama
Sign In

R3

by org.r3js
OverviewDiscussionsAdmin

Measure how big a mesh or model is

r3_component_bounds
Read-onlyIdempotent

The size and place of meshes and imported models, in R3 units (metres): the world-space box around each (min, max, size, centre), the mesh's scale, rotation and parents applied. Name a Mesh, or the root Empty of a Blender model (r3_blender_import makes one, named "_root"), and the box covers it and every mesh under it, with each part listed. Use it before scaling or placing anything relative to its size: to stand a model on the ground, move it so its min.y is the ground height (r3_terrain_height on a terrain); to make it 2 m long, scale by 2 / size. Each answer also gives the project camera's position and lookAt that show it whole on any screen, a phone held upright included: use it to frame a model. Several in one call (up to 20). Works with no R3 tab open, from the project as it is kept; read-only.

Input Schema

NameRequiredDescriptionDefault
projectIdYesThe project, from r3_project_list or r3_project_create.
entityRefsYesMeshes or model root Empties to measure, by entityRef (r3_project_load lists them) or id, e.g. ["truck_root"]. Up to 20.

Output Schema

NameRequiredDescriptionDefault
answerYesThis answer in words: what was done, what R3 measured, decided or refused, and what to do next. The same text as the result's text block. Read it: the fields beside it are the data, this is the guidance.
projectIdYes
componentsYes
unreadableYes
projectNameYes

Schema Changelog

Changes observed during successful MCP inspections.

  1. Changed2 schema fields changed
    • addedOutput schema / properties / components / items / properties / camera
      Added value: +{
+  "anyOf": [
+    {
+      "additionalProperties": false,
+      "properties": {
+        "aspect": {
+          "type": "string"
+        },
+        "distance": {
+          "type": "number"
+        },
+        "entityRef": {
+          "type": "string"
+        },
+        "fov": {
+          "type": "number"
+        },
+        "lookAt": {
+          "additionalProperties": false,
+          "properties": {
+            "x": {
+              "type": "number"
+            },
+            "y": {
+              "type": "number"
+            },
+            "z": {
+              "type": "number"
+            }
+          },
+          "required": [
+            "x",
+            "y",
+            "z"
+          ],
+          "type": "object"
+        },
+        "position": {
+          "additionalProperties": false,
+          "properties": {
+            "x": {
+              "type": "number"
+            },
+            "y": {
+              "type": "number"
+            },
+            "z": {
+              "type": "number"
+            }
+          },
+          "required": [
+            "x",
+            "y",
+            "z"
+          ],
+          "type": "object"
+        }
+      },
+      "required": [
+        "entityRef",
+        "fov",
+        "aspect",
+        "position",
+        "lookAt",
+        "distance"
+      ],
+      "type": "object"
+    },
+    {
+      "type": "null"
+    }
+  ]
+}
    • changedOutput schema / properties / components / items / required
      Previous value: -[
-  "entityRef",
-  "id",
-  "type",
-  "name",
-  "meshes",
-  "measured",
-  "bounds",
-  "parts",
-  "unmeasured"
-]New value: +[
+  "entityRef",
+  "id",
+  "type",
+  "name",
+  "meshes",
+  "measured",
+  "bounds",
+  "camera",
+  "parts",
+  "unmeasured"
+]
  2. Added

TDQS

A4.6/5.0
Behavior4/5

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

Annotations already declare read-only, idempotent, non-destructive, but the description adds real context: it works with no R3 tab open against the stored project, batches up to 20 entities, and returns each child part of a hierarchy. It stops short of discussing failure modes (e.g. unknown entityRef) or result ordering.

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

Conciseness4/5

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

Dense but front-loaded: the output shape comes first, then accepted inputs, then usage recipes, then constraints (20 per call, no tab needed, read-only). A few parentheticals stack up, but every sentence carries information an agent needs.

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

Completeness5/5

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

An output schema exists, yet the description still summarises the payload (box, parts, camera framing), names the project source of truth, and states batch limits and the no-tab requirement. An agent can call this correctly without consulting anything else.

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?

Schema coverage is 100%, so the baseline would be 3, but the description adds meaning beyond the schema: entityRefs may be a Mesh or the root Empty of an imported model (named "<model>_root" by r3_blender_import), and the measured box aggregates the whole subtree. That clarifies accepted input values rather than just repeating types.

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?

States a specific verb (measure) and resource (meshes and imported models) and enumerates exactly what the result contains: world-space box min/max/size/centre, scale, rotation and parents applied. It is clearly distinguishable from siblings like r3_component_read or r3_terrain_height.

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

Usage Guidelines5/5

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

Gives explicit when-to-use drivers (before scaling or placing anything relative to its size) plus concrete recipes: move so min.y equals ground height using r3_terrain_height, or scale by 2 / size for a 2 m model. It also names the companion use case of framing a model via the returned camera position/lookAt.

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

All R3 toolsInspect
Try in Browser
Shareable, User-Owned Context BackendPeople, applications, and agents read, write, and coordinate together in one context lake. Reach it over MCP, a CLI, a Python SDK, or REST.fulcradynamics.comAd

Glama MCP Gateway

Add one secure layer between your agents and this server.

Resources