Single tool with basic schema and description. Tool name 'get-cost' follows verb_noun pattern but description lacks depth on when/why to use it. Input schema present with Zod validation but parameters lack actionable constraints (no enums, ranges, or format guidance). Output is unstructured text rather than typed JSON. No error recovery guidance. Missing parameter descriptions for what vendors/months actually control in the response. No documentation of output structure, making downstream chaining impossible.

• Return structured JSON with typed fields: {vendors: [{name, total_cost, months: [{month, cost, entries: [{date, cost, accountId, productName, regionName}]}]}]}. Document this schema in tool description.
• Expand tool description to 100-150 chars: 'Retrieve cloud cost summaries by vendor (AWS, Azure, GCP) and month. Returns cost breakdowns by account, product, and region. Requires backend API running at localhost:8000.'
• Add enum constraints to parameters: vendors: enum(['AWS', 'Azure', 'GCP']), months: pattern('^\d{4}-\d{2}$'). Include validation error messages in descriptions.
• Implement error classification: return {error: 'API_UNREACHABLE', message: 'Backend at localhost:8000 is not responding. Ensure the cost service is running.', retryable: true} instead of plain text.
• Add pagination support: accept limit (default 20, max 100) and offset parameters. Return total_count and next_offset in response to handle large cost datasets without context explosion.