gather_evidence tool response filtering irrelevant Context, with updated threshold of 0

[jamesbraza]

We were seeing gather_evidence responses like this:

Added 22 pieces of evidence, 0 of which were relevant. Best evidence(s):

1. 

2. 

3. 

4. 

5. 

Status: Paper Count=2 | Relevant Papers=0 | Current Evidence=0 | Current Cost=$0.0086"

There's more to the story here, but this PR at least:

• Documents when we'd have an empty Context.context
• Updates the relevant evidence threshold from 5 to 0
• Filters the gather_evidence tool response for zero-scored Context

[dosubot]

Related Documentation

Checked 1 published document(s). No updates required.

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[Copilot]

Pull Request Overview

This PR improves the gather_evidence tool by filtering out irrelevant context entries and updating the relevance threshold from 5 to 0. The changes address issues where the tool was reporting evidence that wasn't actually useful.

• Updated relevance scoring threshold from 5 to 0 to better identify useful evidence
• Enhanced context filtering to exclude zero-scored (irrelevant) contexts from tool responses
• Added documentation and validation for empty context strings

Reviewed Changes

Copilot reviewed 5 out of 5 changed files in this pull request and generated 1 comment.

Show a summary per file

File	Description
src/paperqa/agents/tools.py	Updated evidence gathering logic to filter contexts with score > 0 and removed relevance counting
src/paperqa/types.py	Added string constraints and documentation for empty context handling
src/paperqa/core.py	Fixed conditional logic for parser usage
tests/test_paperqa.py	Added type annotation and updated assertion to handle whitespace
tests/test_agents.py	Adjusted test assertion to allow tolerance for whitespace in chunks

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[jamesbraza]

This little refactor removes the extra if parser else {}, making the code slightly less stateful

[whitead]

Nice work getting all these cleaned-up

[dosubot]

Documentation Updates

Checked 1 published document(s). No updates required.

^{How did I do? Any feedback?}