Problem

sessions_history has no pagination/offset support and returns at most ~80KB, silently truncating older messages. For long conversations, this makes it impossible to retrieve the complete history.

Context

• The limit appears to be DEFAULT_MAX_BYTES * 2 hardcoded in the tool implementation
• There is no configurable parameter to increase it
• The returned JSON includes "truncated": true but there's no way to request the next page
• The trajectory file (6.9MB) stores everything, but it's a debug/audit format unsuitable for reading

Proposed solution

One or more of:

1. Add offset / pageToken parameters to sessions_history for pagination
2. Add a dedicated session export endpoint that returns the full history without truncation
3. Add a sessions_export tool that produces a clean, readable conversation log (text/markdown, no tool calls, no thinking chains — just user↔assistant messages)
4. Make the output size limit configurable via openclaw.json

Impact

Cannot export complete conversation logs, which is a basic need for reviewing past discussions, sharing context, or archiving.