Server has 4 tools with clear naming (verb_noun pattern) and reasonable descriptions (100-250 chars). Input schemas are present with type definitions. However, output schemas are undocumented, LLMs cannot predict return structure. Error handling is minimal (no recovery guidance). Tool #2 and #3 share the same name 'remove_gamma_watermark' across different files, creating confusion. Parameter descriptions are adequate but lack format constraints (e.g., file path validation rules, base64 size limits not in schema). No tool annotations (readOnlyHint/destructiveHint). Composition is sound, each tool has one responsibility.

• Rename the base64 variant to 'remove_gamma_watermark_from_bytes' or 'remove_gamma_watermark_remote' to disambiguate from the file-based version. Update both server.py and http_server.py to use distinct names.
• Document output schemas in tool descriptions. E.g., 'Returns: {removed: int, units: int, may_remain: bool, cleaned_base64: str, suggested_filename: str}' or add a structured return type annotation visible to the MCP client.
• Add tool annotations: mark remove_gamma_watermark with destructiveHint=true (modifies files), check_gamma_watermark_support with readOnlyHint=true, and both remove_gamma_watermark variants with idempotentHint=true (same input → same output).
• Enhance error messages with recovery guidance. E.g., 'File not found at {path}. Verify the path is absolute and the file exists.' or 'Unsupported format: {ext}. Only .pdf and .pptx are supported.'
• Add JSON Schema constraints: file_path with pattern '^/' (absolute), content_base64 with maxLength (30MB decoded ≈ 40MB base64), filename with pattern '\.(pdf|pptx)$'. This enables client-side validation and LLM self-correction.