PagerDuty MCP Server

list_users_oncall

Identify which users are on call for a PagerDuty schedule during a given time range.

Instructions

List the users on call for a schedule during the specified time range.

Tool call template

Replace each placeholder with a value matching the input schema. Only required parameters are included; add optional parameters as needed.

{
  "id": 1,
  "jsonrpc": "2.0",
  "method": "tools/call",
  "params": {
    "arguments": {
      "schedule_id": "<schedule_id>"
    },
    "name": "list_users_oncall"
  }
}

Input Schema

Name	Required	Description
`since`	No	Start of query range in ISO8601 format
`until`	No	End of query range in ISO8601 format
`include`	No	List of fields to include in the response. If specified, only these fields will be returned for each user on call
`schedule_id`	Yes	The ID of the schedule to query

Output Schema

Name	Required	Description	Default
No arguments

Schema Changelog

Changes observed during successful MCP inspections.

Changed1 schema field changedv4.0.1May 12, 2026

addedInput schema / properties / include

Added value: +{
+  "anyOf": [
+    {
+      "items": {
+        "type": "string"
+      },
+      "type": "array"
+    },
+    {
+      "type": "null"
+    }
+  ],
+  "default": null,
+  "description": "List of fields to include in the response. If specified, only these fields will be returned for each user on call"
+}

Changed8 schema fields changedv3.1.4May 8, 2026
- addedInput schema / additionalProperties
```
Added value: +false
```
- addedInput schema / properties / schedule_id / description
```
Added value: +"The ID of the schedule to query"
```
- removedInput schema / properties / schedule_id / title
```
Removed value: -"Schedule Id"
```
- addedInput schema / properties / since / description
```
Added value: +"Start of query range in ISO8601 format"
```
- removedInput schema / properties / since / title
```
Removed value: -"Since"
```
- addedInput schema / properties / until / description
```
Added value: +"End of query range in ISO8601 format"
```
- removedInput schema / properties / until / title
```
Removed value: -"Until"
```
- changedOutput schema / (root)
```
Previous value: -nullNew value: +{
+  "additionalProperties": true,
+  "type": "object"
+}
```
First observedv1.0.0Aug 18, 2025

TDQS

C2.9/5.0

Behavior2/5

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

With no annotations provided, the description carries full burden for behavioral disclosure. It only states the action but omits details about side effects, safety (e.g., read-only nature), or behaviors when parameters are omitted (e.g., default range when since/until are null).

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Conciseness4/5

Is the description appropriately sized, front-loaded, and free of redundancy?

The description is a single sentence, front-loading the main action and resource. It is concise without being terse, though it could optionally add more context without becoming verbose.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Completeness2/5

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

While the output schema exists, the description does not clarify behavior for missing time range parameters or mention pagination/limits. The tool seems simple, but important contextual details are absent for an agent to confidently invoke it.

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?

The input schema covers all four parameters with descriptions (100% coverage). The description adds no additional meaning beyond the schema, so it meets the baseline expectation for parameter semantics.

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 clearly states the verb 'list' and the resource 'users on call for a schedule during time range'. It is specific and unambiguous. However, it does not differentiate from the sibling tool 'get_oncalls', which may have overlapping functionality.

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?

No guidance is provided on when to use this tool versus alternatives like 'get_oncalls'. There is no mention of prerequisites, limitations, or cases where this tool is inappropriate.

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

Deploy Server