[FEATURE] claude.ai JIRA Data Center connector: add `additional_fields` support to `create_issue`

Preflight Checklist

• [x] I have searched existing requests and this feature hasn't been requested yet
• [x] This is a single feature request (not multiple features)

Problem Statement

When using the claude.ai JIRA Data Center connector's create_issue tool, there is no way to pass custom fields to the Jira REST API. The tool schema only exposes project_key, summary, issue_type, description, labels, priority, and account_id.

Most enterprise Jira projects require custom fields on issue creation (e.g. Assigned
Team, Program, etc. Without a way to pass these, every create call fails with a Jira validation error:

"errorMessages": ["Assigned Team is required."]

This makes the connector unusable for issue creation in any Jira project that enforces required custom fields — which is the norm in enterprise setups.

Proposed Solution

Add an additional_fields parameter (JSON object) to create_issue that is forwarded verbatim to the Jira REST API POST /rest/api/2/issue fields payload.

Example usage:
additional_fields: {
"customfield_10000": [{"key": "XXX-123123"}],
"customfield_10001": "ABC-1234"
}

This is exactly how sooperset/mcp-atlassian implements it and it works reliably.

Alternative Solutions

Currently working around this by running sooperset/mcp-atlassian alongside the claude.ai connector (Docker container) specifically for creates that need custom fields. The claude.ai connector is used for reads and search. This dual-connector setup works but is unnecessary overhead.

The Jira REST API already accepts arbitrary fields in the fields object — the connector just needs to pass them through.

Priority

Critical - Blocking my work

Feature Category

MCP server integration

Use Case Example

1. I ask Claude to create a Jira story linked to an epic with team assignment
2. Claude calls create_issue with the required custom fields in additional_fields
3. Jira accepts the request and creates the issue correctly

Without this, step 2 always fails for any project with required custom fields, blocking all automated issue creation workflows.

Additional Context

• Atlassian's own official remote MCP server has the same limitation (confirmed on Atlassian community forums — their response was to submit feedback)
• sooperset/mcp-atlassian reference implementation: https://github.com/sooperset/mcp-atlassian
• Affects any team using Jira Data Center with required custom fields (common in enterprise/regulated environments)