Opsphere — DevOps & SRE Intelligence

Prometheus label values

prom_label_values

Read-only

List values for a label name (/api/v1/label//values).

Input Schema

Name	Required	Description
`end`	No
`name`	Yes	Label name (e.g. job, namespace, pod)
`match`	No	Optional series selectors (match[])
`start`	No
`context_id`	No	Optional explicit Connection Hub work context (ctx_*). Omit to use the conversation's active workspace; global Hub tools ignore it.

Output Schema

Name	Required	Description	Default
`ok`	Yes
`data`	Yes
`contractVersion`	Yes
`dataSchemaVersion`	Yes

Schema Changelog

Changes observed during successful MCP inspections.

Changed26 schema fields changedOct 26, 2026

changedOutput schema / properties / data / additionalProperties
```
Previous value: -trueNew value: +false
```
removedOutput schema / properties / data / properties / count
```
Removed value: -{
-  "type": "number"
-}
```

removedOutput schema / properties / data / properties / data

Removed value: -{
-  "anyOf": [
-    {
-      "$ref": "#/properties/data/properties/items"
-    },
-    {
-      "$ref": "#/properties/data/properties/items/items"
-    }
-  ]
-}

removedOutput schema / properties / data / properties / error

Removed value: -{
-  "anyOf": [
-    {
-      "type": "string"
-    },
-    {
-      "$ref": "#/properties/data/properties/items/items"
-    }
-  ]
-}

addedOutput schema / properties / data / properties / family

Added value: +{
+  "const": "prometheus",
+  "type": "string"
+}

addedOutput schema / properties / data / properties / gaps

Added value: +{
+  "items": {
+    "type": "string"
+  },
+  "type": "array"
+}

removedOutput schema / properties / data / properties / items

Removed value: -{
-  "items": {
-    "additionalProperties": true,
-    "properties": {},
-    "type": "object"
-  },
-  "type": "array"
-}

removedOutput schema / properties / data / properties / message
```
Removed value: -{
-  "type": "string"
-}
```

removedOutput schema / properties / data / properties / meta

Removed value: -{
-  "$ref": "#/properties/data/properties/items/items"
-}

removedOutput schema / properties / data / properties / nextCursor

Removed value: -{
-  "type": [
-    "string",
-    "null"
-  ]
-}

removedOutput schema / properties / data / properties / ok
```
Removed value: -{
-  "type": "boolean"
-}
```

addedOutput schema / properties / data / properties / operation

Added value: +{
+  "const": "prom_label_values",
+  "type": "string"
+}

removedOutput schema / properties / data / properties / pageInfo

Removed value: -{
-  "$ref": "#/properties/data/properties/items/items"
-}

addedOutput schema / properties / data / properties / partial
```
Added value: +{
+  "type": "boolean"
+}
```

addedOutput schema / properties / data / properties / records

Added value: +{
+  "items": {
+    "additionalProperties": false,
+    "properties": {
+      "createdAt": {
+        "type": "string"
+      },
+      "environment": {
+        "type": "string"
+      },
+      "facts": {
+        "items": {
+          "additionalProperties": false,
+          "properties": {
+            "name": {
+              "type": "string"
+            },
+            "value": {
+              "anyOf": [
+                {
+                  "type": "string"
+                },
+                {
+                  "type": "number"
+                },
+                {
+                  "type": "boolean"
+                },
+                {
+                  "type": "null"
+                },
+                {
+                  "items": {
+                    "type": [
+                      "string",
+                      "number",
+                      "boolean",
+                      "null"
+                    ]
+                  },
+                  "type": "array"
+                }
+              ]
+            }
+          },
+          "required": [
+            "name",
+            "value"
+          ],
+          "type": "object"
+        },
+        "type": "array"
+      },
+      "id": {
+        "type": "string"
+      },
+      "key": {
+        "type": "string"
+      },
+      "labels": {
+        "items": {
+          "$ref": "#/properties/data/properties/records/items/properties/facts/items"
+        },
+        "type": "array"
+      },
+      "message": {
+        "type": "string"
+      },
+      "metric": {
+        "type": "string"
+      },
+      "name": {
+        "type": "string"
+      },
+      "severity": {
+        "type": "string"
+      },
+      "status": {
+        "type": "string"
+      },
+      "summary": {
+        "type": "string"
+      },
+      "tags": {
+        "items": {
+          "type": "string"
+        },
+        "type": "array"
+      },
+      "timestamp": {
+        "type": "string"
+      },
+      "title": {
+        "type": "string"
+      },
+      "type": {
+        "type": "string"
+      },
+      "unit": {
+        "type": "string"
+      },
+      "updatedAt": {
+        "type": "string"
+      },
+      "url": {
+        "type": "string"
+      },
+      "value": {
+        "type": "number"
+      }
+    },
+    "required": [
+      "facts",
+      "labels"
+    ],
+    "type": "object"
+  },
+  "type": "array"
+}

removedOutput schema / properties / data / properties / results

Removed value: -{
-  "$ref": "#/properties/data/properties/items"
-}

removedOutput schema / properties / data / properties / status

Removed value: -{
-  "type": [
-    "string",
-    "number"
-  ]
-}

addedOutput schema / properties / data / properties / summary
```
Added value: +{
+  "type": "string"
+}
```
removedOutput schema / properties / data / properties / text
```
Removed value: -{
-  "type": "string"
-}
```
addedOutput schema / properties / data / properties / total / minimum
```
Added value: +0
```
changedOutput schema / properties / data / properties / total / type
```
Previous value: -"number"New value: +"integer"
```
addedOutput schema / properties / data / properties / truncated
```
Added value: +{
+  "type": "boolean"
+}
```

addedOutput schema / properties / data / properties / warnings

Added value: +{
+  "items": {
+    "type": "string"
+  },
+  "type": "array"
+}

addedOutput schema / properties / data / required

Added value: +[
+  "family",
+  "operation",
+  "records",
+  "total",
+  "partial",
+  "truncated",
+  "warnings",
+  "gaps"
+]

addedOutput schema / properties / dataSchemaVersion

Added value: +{
+  "const": 2,
+  "type": "number"
+}

changedOutput schema / required

Previous value: -[
-  "contractVersion",
-  "ok",
-  "data"
-]New value: +[
+  "contractVersion",
+  "dataSchemaVersion",
+  "ok",
+  "data"
+]

First observedOct 15, 2026

TDQS

B3.4/5.0

Behavior3/5

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

Annotations already declare readOnlyHint, openWorldHint=false, and destructiveHint=false, so safety behavior is covered. The description adds little beyond the endpoint path; it does not mention authentication, rate limits, or result shape, though an output schema exists to cover return values.

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?

A single sentence with zero waste, front-loading the purpose and including the API endpoint. Nothing is redundant or overly verbose.

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 low complexity, annotations covering safety, and an output schema, the description is largely complete for invocation. It could be improved by adding brief usage guidance for the optional start/end/match parameters, but nothing critical is missing.

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 coverage is 60%, so parameters like name, match, and context_id are documented in the schema. The description does not explain the start/end parameters or add meaning beyond what the schema provides, so the baseline of 3 is appropriate.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Purpose4/5

Does the description clearly state what the tool does and how it differs from similar tools?

The description states a specific verb and resource ('List values for a label name') and includes the API endpoint, making the operation unambiguous. It does not differentiate from Prometheus siblings such as prom_query or prom_query_range, leaving that inference to the agent.

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 explicit guidance on when to use this tool versus prom_query or prom_query_range, nor any conditions or prerequisites. Usage is only implied by the name and endpoint.

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

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