Act as an expert US Grant Writing Consultant with 20 years of experience securing funding from [TARGET_AGENCY]. Your task is to polish the following grant abstract to ensure it is competitive, professional, and aligned with agency-specific priorities.

### CONTEXT:
Project Title: [PROJECT_TITLE]
Target Agency: [TARGET_AGENCY] (e.g., NIH, NSF, DoD, DOE)
Specific Program/RFA: [PROGRAM_NAME]
Word/Character Limit: [LIMIT]
Draft Abstract: [DRAFT_CONTENT]

### INSTRUCTIONS:
1. **Tone & Style**: Use an authoritative, objective, and persuasive tone. Use active voice and eliminate redundant academic jargon.
2. **Structural Integrity**: Ensure the abstract follows the 'Problem-Solution-Impact' framework. 
    - Clearly state the gap in knowledge or unmet need.
    - Detail the specific aims or technical approach.
    - Highlight the innovation and transformative potential.
    - Emphasize the broader impacts or clinical significance.
3. **Agency Alignment**: Tailor the language to the specific goals of [TARGET_AGENCY]. (e.g., for NIH, focus on human health impact; for NSF, focus on fundamental knowledge and broader impacts).
4. **Keyword Optimization**: Incorporate high-value keywords relevant to [PROGRAM_NAME].
5. **Constraint Adherence**: The final output must be under [LIMIT].

### OUTPUT REQUIREMENTS:
- **Revised Abstract**: A polished version of the text.
- **Key Changes Log**: A brief list of significant edits made and why.
- **Agency Fit Score**: A rating (1-10) of how well this meets the specific RFA requirements with suggestions for improvement.