cesium-mcp

addMarker

Add a point marker at specified latitude and longitude. Provides an entityId for later removal.

Instructions

Add a point marker at geographic coordinates. Returns { success, data: { entityId }, message? }; keep entityId for removeEntity.

Input Schema

TableJSON Schema

Name	Required	Description	Default
`id`	No	Custom layer ID (auto-generated if omitted)
`size`	No	Point size (pixels)
`color`	No	Marker color (CSS format)	#3B82F6
`label`	No	Label text
`latitude`	Yes	Latitude (-90 to 90)
`longitude`	Yes	Longitude (-180 to 180)
`sessionId`	No	Target browser session ID for multi-browser routing (optional)

Output Schema

TableJSON Schema

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

Schema Changelog

Changes observed during successful MCP inspections.

Changed1 schema field changedv1.139.19Aug 19, 2026

changedOutput schema / (root)

Previous value: -nullNew value: +{
+  "additionalProperties": false,
+  "properties": {
+    "data": {
+      "additionalProperties": false,
+      "properties": {
+        "entityId": {
+          "type": "string"
+        }
+      },
+      "required": [
+        "entityId"
+      ],
+      "type": "object"
+    },
+    "error": {
+      "type": "string"
+    },
+    "message": {
+      "type": "string"
+    },
+    "success": {
+      "type": "boolean"
+    }
+  },
+  "required": [
+    "success"
+  ],
+  "type": "object"
+}

Changed1 schema field changedv1.139.18Aug 12, 2026
- removedInput schema / $schema
```
Removed value: -"http://json-schema.org/draft-07/schema#"
```
Changed11 schema fields changedv1.139.17Jul 29, 2026
- addedInput schema / properties / color / maxLength
```
Added value: +64
```
- addedInput schema / properties / color / minLength
```
Added value: +1
```
- addedInput schema / properties / id / maxLength
```
Added value: +100
```
- addedInput schema / properties / id / minLength
```
Added value: +1
```
- addedInput schema / properties / label / maxLength
```
Added value: +200
```
- addedInput schema / properties / latitude / maximum
```
Added value: +90
```
- addedInput schema / properties / latitude / minimum
```
Added value: +-90
```
- addedInput schema / properties / longitude / maximum
```
Added value: +180
```
- addedInput schema / properties / longitude / minimum
```
Added value: +-180
```
- addedInput schema / properties / size / maximum
```
Added value: +128
```
- addedInput schema / properties / size / minimum
```
Added value: +1
```

Changed7 schema fields changedv1.139.14Apr 30, 2026

changedInput schema / properties / color / description

Previous value: -"标注颜色（CSS 格式）"New value: +"Marker color (CSS format)"

changedInput schema / properties / id / description

Previous value: -"自定义图层ID（不传则自动生成）"New value: +"Custom layer ID (auto-generated if omitted)"

changedInput schema / properties / label / description

Previous value: -"标注文本"New value: +"Label text"

changedInput schema / properties / latitude / description

Previous value: -"纬度（-90 ~ 90）"New value: +"Latitude (-90 to 90)"

changedInput schema / properties / longitude / description

Previous value: -"经度（-180 ~ 180）"New value: +"Longitude (-180 to 180)"

addedInput schema / properties / sessionId

Added value: +{
+  "description": "Target browser session ID for multi-browser routing (optional)",
+  "type": "string"
+}

changedInput schema / properties / size / description

Previous value: -"点大小（像素）"New value: +"Point size (pixels)"

First observedv1.139.4Mar 15, 2026

TDQS

A4.2/5.0

Behavior4/5

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

Annotations already indicate a non-read-only, non-destructive operation, so the bar is lower. The description adds valuable behavioral context beyond annotations: it discloses the return shape ({ success, data: { entityId }, message? }) and instructs to keep entityId for removeEntity, which helps the agent understand lifecycle management. No contradictions with annotations.

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 two sentences, front-loaded with the core purpose, and includes essential return information without any fluff. Every sentence earns its place, making it highly efficient for an AI agent to parse.

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?

Given the tool's simplicity and the presence of a full input schema and output schema, the description is adequate. It covers the primary action, return value, and a key follow-up (removeEntity). It could optionally mention that this is for map layers, but that is reasonably inferable from the sibling tool names and parameters.

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 all parameters. The description does not add significant parameter-specific meaning beyond what the schema provides. It reinforces that coordinates are geographic but does not provide additional semantics, so baseline 3 is appropriate.

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 action ('Add a point marker') and the resource ('at geographic coordinates'). It distinguishes from sibling tools like addPolygon or addPolyline by explicitly specifying 'point marker.' The return format is also mentioned, leaving no ambiguity about what the tool does.

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

Usage Guidelines4/5

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

The description provides clear context for when to use the tool: adding point markers at coordinates. It does not explicitly mention alternatives or exclusions, but the specificity of 'point marker' implicitly differentiates it from adding other entity types. No misleading guidance is present.

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