List MongoDB Atlas clusters in a project using its project ID. Retrieve cluster information to manage Atlas resources.
List MongoDB Atlas clusters
| Name | Required | Description | Default |
|---|---|---|---|
| projectId | No | Atlas project ID to filter clusters |
| Name | Required | Description | Default |
|---|---|---|---|
| clusters | Yes | ||
| projectId | No | ||
| totalCount | Yes | ||
| projectName | No |
Changes observed during successful MCP inspections.
v2.0.0Input schema / additionalPropertiesAdded value: +falsev1.14.0Output schema / (root)Previous value: -nullNew value: +{
+ "$schema": "http://json-schema.org/draft-07/schema#",
+ "additionalProperties": false,
+ "properties": {
+ "clusters": {
+ "items": {
+ "anyOf": [
+ {
+ "additionalProperties": false,
+ "properties": {
+ "clusterName": {
+ "type": "string"
+ },
+ "projectId": {
+ "type": "string"
+ },
+ "projectName": {
+ "type": "string"
+ }
+ },
+ "type": "object"
+ },
+ {
+ "additionalProperties": false,
+ "properties": {
+ "connectionStrings": {
+ "additionalProperties": {},
+ "propertyNames": {
+ "type": "string"
+ },
+ "type": "object"
+ },
+ "instanceSize": {
+ "type": "string"
+ },
+ "instanceType": {
+ "enum": [
+ "FREE",
+ "DEDICATED",
+ "FLEX"
+ ],
+ "type": "string"
+ },
+ "mongoDBVersion": {
+ "type": "string"
+ },
+ "name": {
+ "type": "string"
+ },
+ "paused": {
+ "type": "boolean"
+ },
+ "processIds": {
+ "items": {
+ "type": "string"
+ },
+ "type": "array"
+ },
+ "provider": {
+ "type": "string"
+ },
+ "region": {
+ "type": "string"
+ },
+ "state": {
+ "enum": [
+ "IDLE",
+ "CREATING",
+ "UPDATING",
+ "DELETING",
+ "REPAIRING"
+ ],
+ "type": "string"
+ }
+ },
+ "required": [
+ "instanceType",
+ "paused"
+ ],
+ "type": "object"
+ }
+ ]
+ },
+ "type": "array"
+ },
+ "projectId": {
+ "type": "string"
+ },
+ "projectName": {
+ "type": "string"
+ },
+ "totalCount": {
+ "type": "number"
+ }
+ },
+ "required": [
+ "clusters",
+ "totalCount"
+ ],
+ "type": "object"
+}v1.11.0Input schema / additionalPropertiesRemoved value: -falsev1.0.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnlyHint=true, openWorldHint=true, and destructiveHint=false, covering the safety profile. The description adds no behavioral context beyond the tool name, such as optional filtering, output scope, pagination, or authentication requirements. It does not contradict annotations, but it contributes nothing new.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.
Is the description appropriately sized, front-loaded, and free of redundancy?
The description is one short, front-loaded sentence with no filler or unnecessary detail. It is maximally concise, though it essentially restates the tool name without elaboration.
Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.
Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?
The tool is simple (1 optional parameter, full schema coverage, output schema present, and read-only annotations), so the minimal description combined with structured fields is sufficient for basic invocation. It would benefit from explicitly noting that omitting projectId returns clusters across accessible projects.
Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.
Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?
The input schema has 100% coverage and clearly describes the single projectId parameter ('Atlas project ID to filter clusters'). The description adds no parameter-level information, so the baseline score of 3 applies.
Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.
Does the description clearly state what the tool does and how it differs from similar tools?
The description uses a specific verb ('List') and resource ('MongoDB Atlas clusters'), making the core operation clear. It does not mention the optional projectId filter that would scope results, so it lacks some specificity but is still distinctly about listing clusters.
Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.
Does the description explain when to use this tool, when not to, or what alternatives exist?
There is no guidance on when to use this tool over siblings such as atlas-inspect-cluster (for cluster details) or atlas-list-projects (for project IDs). The description provides zero context for tool selection.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.