align query tool name

[rejojer]

Summary

This PR aligns the long-document retrieval tool name exposed by the query agent with the name referenced in the agent instructions.

What Changed

• renamed the internal PageIndex retrieval implementation to a private helper to avoid naming conflicts
• exposed the query agent tool as pageindex_retrieve so the registered tool name matches the prompt instructions
• updated query tests to assert the new tool name and added a guard that checks the instructions and registered tool stay aligned

Why

The query agent instructions told the model to call pageindex_retrieve, but the actual registered tool name was retrieve. That mismatch made long-document retrieval less reliable because the model could be instructed to call a tool name that did not exist.

Validation

• `python3 -m pytest -q tests/test_query.py -k 'TestBuildQueryAgent or TestPageindexRetrieve'

[rejojer]

Code review

No issues found. Checked for bugs and CLAUDE.md compliance.

🤖 Generated with Claude Code

_{- If this code review was useful, please react with 👍. Otherwise, react with 👎.}