feat: added ConcisenessEvaluator

[poshinchen]

Description

Added ConcisenessEvaluator based on AgentCore's ConcisenessEvaluator.

Scores

• Perfectly Concise (1.0): delivers exactly what was asked with no unnecessary content
• Partially Concise (0.5): minor extra wording but still focused
• Not Concise (0.0): verbose, repetitive, or includes substantial unnecessary content

Related Issues

#103

Documentation PR

TBD

Type of Change

New feature

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

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, or no new docs are needed
• My changes generate no new warnings
• Any dependent changes have been merged and published

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[Unshure]

Do we need to update the readme with this new evaluator?

Also, should we add integ tests?