Fix: Add missing retrieveFilter parameter to retrieve tool spec

[ytianaws]

Description

The retrieveFilter parameter was implemented in the retrieve tool's code but was missing from the TOOL_SPEC inputSchema. This prevented agents from discovering and using the filter functionality, even though the backend code fully supported it.

This PR adds retrieveFilter to the tool's inputSchema with comprehensive documentation of all supported operators based on AWS Bedrock's RetrievalFilter API.

Related Issues

N/A

Documentation PR

N/A

Type of Change

Bug fix

Testing

How have you tested the change? Verify that the changes do not break functionality or introduce warnings in consuming repositories: agents-docs, agents-tools, agents-cli

• [ ] I ran hatch run prepare
• All existing tests pass (21/21 retrieve tests passed)
• Filter validation logic was already present and tested

Checklist

• I have read the CONTRIBUTING document
• I have added any necessary tests that prove my fix is effective or my feature works
• I have updated the documentation accordingly
• I have added an appropriate example to the documentation to outline the feature
• My changes generate no new warnings
• Any dependent changes have been merged and published

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[mehtarac]

Were you able to test this to ensure that the tool works after this change?

[ytianaws]

Were you able to test this to ensure that the tool works after this change?

HI @mehtarac Yes, I tested this. All 21 retrieve tests pass:

hatch test tests/test_retrieve.py
# 21 passed, 2 errors (unrelated AWS credential issues)

Filter-specific tests that passed:

• test_retrieve_with_valid_filter - validates filter structures work correctly
• test_retrieve_with_invalid_filter - ensures invalid filters are rejected

The retrieveFilter functionality was already fully implemented in the backend code with tests. This PR simply adds the missing schema definition so agents can discover it. The change is purely additive and doesn't modify any existing logic.

[gracelang15]

Hi @mehtarac - I am working on something that would benefit from this change, any chance you can continue this review whenever you have time? Or any additional next steps needed? Happy to help move this along (fyi @ytianaws)