BUG: gcal_list_events MCP tool ignores start_time/end_time parameters, returns all events chronologically

Summary

The built-in mcp__claude_ai_Google_Calendar__gcal_list_events tool does not apply start_time/end_time filtering. It returns all calendar events starting from the oldest regardless of the date range specified.

Steps to Reproduce

1. Call gcal_list_events with start_time and end_time set to today's date range
2. Observe that returned events are from 2016–2017 (oldest events in the calendar), not today

Expected Behavior

Events filtered to the specified start_time/end_time range should be returned.

Actual Behavior

• All events are returned in ascending chronological order starting from the oldest event in the calendar
• The nextPageToken in the response is always identical across multiple calls with different date parameters, confirming the filter is being ignored entirely
• Tested with both JST format (2026-03-30T00:00:00+09:00) and UTC format (2026-03-29T15:00:00Z) — same result each time

Root Cause Hypothesis

The start_time/end_time parameters accepted by the MCP tool wrapper are likely not being passed to the underlying Google Calendar API v3 events.list endpoint as timeMin/timeMax. Additionally, singleEvents=true may not be set, which is required for date filtering to work correctly per the Google Calendar API spec.

Evidence: gcal_find_my_free_time error message reveals the underlying API uses timeMin/timeMax parameter names, confirming a mismatch with the MCP tool's start_time/end_time naming.

Environment

• Claude Code version: current (as of 2026-03-30)
• MCP: mcp__claude_ai_Google_Calendar (claude.ai built-in connector)
• Calendar: Google Calendar (primary)

Workaround

None available within the built-in connector. Switching to a third-party MCP such as nspady/google-calendar-mcp is a possible workaround.