Bug

buildQueryString() in src/utils/gitlab-api.ts calls String(value) on array parameters, converting ["failed", "success"] to the string "failed,success". GitLab Rails API expects scope[]=failed&scope[]=success.

Impact

Any tool passing array query params to REST API gets 400 Bad Request. Affected:

• browse_pipelines jobs action (job_scope)
• browse_pipelines triggers action (trigger_scope)
• browse_members actions (user_ids)
• browse_merge_requests list action (approved_by_ids)
• Any other array params passed through toQuery() -> buildQueryString()

Reproduction

browse_pipelines(action: "jobs", project_id: "123", pipeline_id: "456", job_scope: ["created","pending","running","failed","success","canceled","skipped"])

Returns: 400 Bad Request - scope does not have a valid value

Root Cause

1. registry.ts: queryOptions.scope = job_scope (array)
2. toQuery(): passes array through unchanged
3. buildQueryString(): String(["failed","success"]) -> "failed,success"
4. URL: ?scope=failed%2Csuccess (invalid)

Fix

• buildQueryString() handles arrays via searchParams.append(key[], item) (Rails convention)
• toQuery() return type updated to preserve arrays