Polarion MCP Server

postProjectCustomFields

Creates Custom Fields in a specific Polarion project context. Use dry_run to validate arguments and preview the exact request before creating resources.

Instructions

Creates a list of Custom Fields in the Project context. Scope: one project (requires a project ID). To act across all projects, use postGlobalCustomFields instead. Effect: creates a new resource. Repeating this call may create additional resources; it is not guaranteed idempotent. Tip: set dry_run: true first to validate the arguments and preview the exact request without sending it to Polarion. The executor returns this preview as normal text, and as structured content when the tool declares an output schema.

Input Schema

Name	Required	Description
`dry_run`	No	If true, validates the request and returns the exact request that would be sent to Polarion — with the Authorization header redacted and any binary payload summarized by byte length — without actually sending it.
`projectId`	Yes	The Polarion project ID (its URL segment, e.g. `myproject`), case-sensitive. Required to scope the request to one project. If the ID is unknown, ask the user; getProjects lists IDs only with global read access.
`requestBody`	Yes	Custom Fields Body

Output Schema

Name	Required	Description	Default
`data`	No

Schema Changelog

Changes observed during successful MCP inspections.

Changed1 schema field changedv1.4.4Oct 29, 2026

changedInput schema / properties / projectId / description

Previous value: -"The Polarion project ID (its URL segment, e.g. `myproject`), case-sensitive. Required to scope the request to one project; call getProjects to list valid IDs."New value: +"The Polarion project ID (its URL segment, e.g. `myproject`), case-sensitive. Required to scope the request to one project. If the ID is unknown, ask the user; getProjects lists IDs only with global read access."

Changed9 schema fields changedv1.3.1Oct 22, 2026

removedOutput schema / properties / data / items / properties / id / example
```
Removed value: -"MyProjectId/workitems/epic"
```

changedOutput schema / properties / data / items / properties / id / type

Previous value: -"string"New value: +[
+  "string",
+  "number",
+  "integer",
+  "boolean",
+  "null"
+]

removedOutput schema / properties / data / items / properties / links / properties / self / example

Removed value: -"server-host-name/application-path/projects/MyProjectId/customfields/workitems/epic"

changedOutput schema / properties / data / items / properties / links / properties / self / type

Previous value: -"string"New value: +[
+  "string",
+  "number",
+  "integer",
+  "boolean",
+  "null"
+]

changedOutput schema / properties / data / items / properties / links / type
```
Previous value: -"object"New value: +[
+  "object",
+  "null"
+]
```
removedOutput schema / properties / data / items / properties / type / enum
```
Removed value: -[
-  "customfields"
-]
```

changedOutput schema / properties / data / items / properties / type / type

Previous value: -"string"New value: +[
+  "string",
+  "number",
+  "integer",
+  "boolean",
+  "null"
+]

changedOutput schema / properties / data / items / type

Previous value: -"object"New value: +[
+  "object",
+  "null"
+]

changedOutput schema / properties / data / type

Previous value: -"array"New value: +[
+  "array",
+  "null"
+]

Changed2 schema fields changedv1.2.0Sep 17, 2026

changedInput schema / properties / dry_run / description

Previous value: -"If true, validate and return the request that would be sent without calling Polarion."New value: +"If true, validates the request and returns the exact request that would be sent to Polarion — with the Authorization header redacted and any binary payload summarized by byte length — without actually sending it."

changedInput schema / properties / projectId / description

Previous value: -"The Project ID."New value: +"The Polarion project ID (its URL segment, e.g. `myproject`), case-sensitive. Required to scope the request to one project; call getProjects to list valid IDs."

Changed1 schema field changedv1.1.0Sep 11, 2026

changedOutput schema / (root)

Previous value: -nullNew value: +{
+  "properties": {
+    "data": {
+      "items": {
+        "properties": {
+          "id": {
+            "example": "MyProjectId/workitems/epic",
+            "type": "string"
+          },
+          "links": {
+            "properties": {
+              "self": {
+                "example": "server-host-name/application-path/projects/MyProjectId/customfields/workitems/epic",
+                "type": "string"
+              }
+            },
+            "type": "object"
+          },
+          "type": {
+            "enum": [
+              "customfields"
+            ],
+            "type": "string"
+          }
+        },
+        "type": "object"
+      },
+      "type": "array"
+    }
+  },
+  "type": "object"
+}

AddedSep 7, 2026

TDQS

A4.3/5.0

Behavior4/5

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

Annotations already declare readOnly=false, idempotent=false, and openWorld=true. The description adds that this creates a new resource, that repeating may create additional resources, and that dry_run previews the exact request without sending it, though it does not mention permission requirements or error handling.

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?

Purpose, scope, and the alternative sibling are front-loaded. The later sentences about non-idempotency and dry-run output are useful, but the executor/output-schema sentence is somewhat meta and adds minor verbosity.

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?

For a nested create operation with an output schema and annotations, the description covers scope, the global alternative, non-idempotency, and dry_run behavior. It leaves request-body field semantics and validation rules to the schema, which is reasonable given high schema coverage.

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 already documents the three parameters including nested request body structure. The description only reinforces that projectId is required and that dry_run previews the request, adding little parameter-level semantics beyond the schema.

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?

States a specific verb and resource: "Creates a list of Custom Fields in the Project context." It also names the scope (one project) and explicitly distinguishes itself from the sibling `postGlobalCustomFields`.

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

Usage Guidelines5/5

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

Explicitly says to use this tool for one project and to use `postGlobalCustomFields` instead for all projects. The dry-run tip adds a concrete workflow recommendation before invoking the real create.

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

Deploy Server