Single tool with adequate schema and parameter descriptions, but lacks output schema documentation and error recovery guidance. Tool name follows verb_noun pattern (read_notebook). Input schema is complete with types and descriptions for all 5 parameters. However, the return type is documented only as 'str' in the function signature, no structured output schema is provided. Error handling returns generic error strings rather than actionable recovery guidance. The tool description (194 chars) is within baseline range but lacks WHEN to use it and prerequisites. No tool annotations (readOnlyHint, etc.) despite being read-only.

• Document output schema: return type should be structured as {success: bool, content: string, cell_count: int, error?: string} or similar, not bare string.
• Add actionable error messages: catch FileNotFoundError separately and suggest 'Notebook not found at {path}. Check the path is correct and the file exists.'; catch nbformat.ValidationError and suggest 'Notebook format invalid. Ensure it is a valid .ipynb file.'
• Expand tool description to 150-250 chars: explain use case (debugging, analysis), mention filter combinations, and note that output is formatted for LLM consumption.
• Add readOnlyHint=true annotation to signal safety and idempotency to LLMs.
• Validate 'path' parameter: reject paths containing '..' or starting with '/', restrict to a configured notebook directory, and return clear error if validation fails.