cesium-mcp

measure

Determine distance or area between geographic coordinates, returning the value in unit and an optional map display with segment IDs.

Instructions

Measure distance or area between geographic coordinate tuples. Returns { success, data: { mode, value, unit, segments?, id? }, message? }.

Input Schema

TableJSON Schema

Name	Required	Description
`id`	No	Custom measurement entity ID
`mode`	Yes	Measurement mode: distance or area
`positions`	Yes	Coordinate array [[lon, lat, alt?], ...]
`sessionId`	No	Target browser session ID for multi-browser routing (optional)
`showOnMap`	No	Whether to display measurement result on map

Output Schema

TableJSON Schema

Name	Required	Description	Default
`data`	No
`error`	No
`message`	No
`success`	Yes

Schema Changelog

Changes observed during successful MCP inspections.

Changed2 schema fields changedv1.139.19Aug 19, 2026

addedInput schema / properties / positions / items / items
```
Added value: +{
+  "type": "number"
+}
```

changedOutput schema / (root)

Previous value: -nullNew value: +{
+  "additionalProperties": false,
+  "properties": {
+    "data": {
+      "additionalProperties": false,
+      "properties": {
+        "id": {
+          "type": "string"
+        },
+        "mode": {
+          "enum": [
+            "distance",
+            "area"
+          ],
+          "type": "string"
+        },
+        "segments": {
+          "items": {
+            "minimum": 0,
+            "type": "number"
+          },
+          "type": "array"
+        },
+        "unit": {
+          "type": "string"
+        },
+        "value": {
+          "minimum": 0,
+          "type": "number"
+        }
+      },
+      "required": [
+        "mode",
+        "value",
+        "unit"
+      ],
+      "type": "object"
+    },
+    "error": {
+      "type": "string"
+    },
+    "message": {
+      "type": "string"
+    },
+    "success": {
+      "type": "boolean"
+    }
+  },
+  "required": [
+    "success"
+  ],
+  "type": "object"
+}

Changed6 schema fields changedv1.139.18Aug 12, 2026

removedInput schema / $schema

Removed value: -"http://json-schema.org/draft-07/schema#"

removedInput schema / properties / positions / items / anyOf

Removed value: -[
-  {
-    "items": [
-      {
-        "description": "Longitude in decimal degrees",
-        "maximum": 180,
-        "minimum": -180,
-        "type": "number"
-      },
-      {
-        "description": "Latitude in decimal degrees",
-        "maximum": 90,
-        "minimum": -90,
-        "type": "number"
-      }
-    ],
-    "maxItems": 2,
-    "minItems": 2,
-    "type": "array"
-  },
-  {
-    "items": [
-      {
-        "$ref": "#/properties/positions/items/anyOf/0/items/0"
-      },
-      {
-        "$ref": "#/properties/positions/items/anyOf/0/items/1"
-      },
-      {
-        "description": "Optional height in meters",
-        "maximum": 50000000,
-        "minimum": -12000,
-        "type": "number"
-      }
-    ],
-    "maxItems": 3,
-    "minItems": 3,
-    "type": "array"
-  }
-]

addedInput schema / properties / positions / items / maxItems
```
Added value: +3
```
addedInput schema / properties / positions / items / minItems
```
Added value: +2
```

addedInput schema / properties / positions / items / prefixItems

Added value: +[
+  {
+    "description": "Longitude in decimal degrees",
+    "maximum": 180,
+    "minimum": -180,
+    "type": "number"
+  },
+  {
+    "description": "Latitude in decimal degrees",
+    "maximum": 90,
+    "minimum": -90,
+    "type": "number"
+  },
+  {
+    "description": "Optional height in meters",
+    "maximum": 50000000,
+    "minimum": -12000,
+    "type": "number"
+  }
+]

addedInput schema / properties / positions / items / type
```
Added value: +"array"
```

Changed9 schema fields changedv1.139.17Jul 29, 2026

addedInput schema / properties / id / maxLength
```
Added value: +100
```
addedInput schema / properties / id / minLength
```
Added value: +1
```

addedInput schema / properties / positions / items / anyOf

Added value: +[
+  {
+    "items": [
+      {
+        "description": "Longitude in decimal degrees",
+        "maximum": 180,
+        "minimum": -180,
+        "type": "number"
+      },
+      {
+        "description": "Latitude in decimal degrees",
+        "maximum": 90,
+        "minimum": -90,
+        "type": "number"
+      }
+    ],
+    "maxItems": 2,
+    "minItems": 2,
+    "type": "array"
+  },
+  {
+    "items": [
+      {
+        "$ref": "#/properties/positions/items/anyOf/0/items/0"
+      },
+      {
+        "$ref": "#/properties/positions/items/anyOf/0/items/1"
+      },
+      {
+        "description": "Optional height in meters",
+        "maximum": 50000000,
+        "minimum": -12000,
+        "type": "number"
+      }
+    ],
+    "maxItems": 3,
+    "minItems": 3,
+    "type": "array"
+  }
+]

addedInput schema / properties / positions / items / description

Added value: +"Coordinate tuple [longitude, latitude, optional height]"

removedInput schema / properties / positions / items / items
```
Removed value: -{
-  "type": "number"
-}
```
removedInput schema / properties / positions / items / maxItems
```
Removed value: -3
```
removedInput schema / properties / positions / items / minItems
```
Removed value: -2
```
removedInput schema / properties / positions / items / type
```
Removed value: -"array"
```
addedInput schema / properties / positions / maxItems
```
Added value: +10000
```

Addedv1.139.14Apr 30, 2026

TDQS

A3.8/5.0

Behavior3/5

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

The description discloses the return structure, which adds context beyond annotations. However, it does not mention potential side effects such as displaying on a map (showOnMap parameter) or session context. Annotations are all false, so the description carries the burden but only partially covers behavior.

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 concise with a single sentence stating the purpose, followed by the return format. All sentences are informative with no redundancy.

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 5-parameter tool with a rich schema and output schema, the description is mostly complete. It could benefit from clarifying units or the minimum positions for area, but overall it provides sufficient context.

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

Parameters3/5

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

Schema description coverage is 100%, so the schema fully documents the parameters. The description does not add additional parameter semantics beyond restating the purpose.

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 clearly states the tool measures distance or area between coordinate tuples, using a specific verb and resource. This distinguishes it from sibling tools with no ambiguity.

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 description implies usage when measurement is needed, but does not explicitly provide when-to-use guidance or contrast with alternatives. The purpose is clear enough that no alternative tool is obvious, but explicit guidance is missing.

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