prometheus_list_label_values
List all values for a Prometheus label, with optional series selector filter, to discover entities like job names or instances for building targeted PromQL queries.
Instructions
List all values for a specific label from Prometheus.
Wraps GET /api/v1/label/{label_name}/values. Returns all distinct
values for the named label across all time series, optionally filtered
by a series selector.
Use this to discover what entities exist for a given label dimension — for example, which jobs are running, which instances are scraped, or which namespaces have metrics. This is essential for building targeted PromQL queries during investigation.
Examples:
- Use when: "What jobs does Prometheus scrape?"
→ label='job'; read the values list.
- Use when: "What instances are in the 'node-exporter' job?"
→ label='instance', match='{job="node-exporter"}'.
- Use when: "What namespaces have metrics?"
→ label='namespace'.
- Don't use when: You want metric names
(call prometheus_list_metrics — has substring filtering).
- Don't use when: You want current metric values
(call prometheus_query with a PromQL expression).
Returns:
dict with label / match / total_count /
returned_count / truncated / values (sorted list).
Input Schema
| Name | Required | Description | Default |
|---|---|---|---|
| label | Yes | Label name to retrieve values for. Examples: 'job' (list all job names), 'instance' (list all instances), '__name__' (list all metric names — same as prometheus_list_metrics). | |
| match | No | Optional series selector to restrict which series the label values come from. Example: 'up' returns label values only from the 'up' metric. Example: '{job="node"}' returns label values only from the node job. Leave empty to get values across all series. | |
| instance | No | Target instance name (omit for default instance) |
Output Schema
| Name | Required | Description | Default |
|---|---|---|---|
| label | Yes | ||
| match | Yes | ||
| values | Yes | ||
| truncated | Yes | ||
| total_count | Yes | ||
| returned_count | Yes |