ChartMogul MCP Server

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

With no annotations provided, the description carries the full burden. It discloses the return format ('Returns import summary with created invoices and errors') and mentions it's for historical data import, but doesn't address permission requirements, rate limits, idempotency, or error handling details that would be important for a data import operation.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

The description is appropriately front-loaded with the core purpose, followed by detailed parameter specifications. While comprehensive, the nested object specifications are lengthy but necessary given the complex data structure. Every sentence serves a clear purpose.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

For a complex mutation tool with no annotations and no output schema, the description does well by explaining the return format and providing extensive parameter details. However, it could better address behavioral aspects like error conditions or idempotency given the tool's complexity.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Despite 0% schema description coverage, the description comprehensively explains both parameters: 'data' is detailed as 'invoices data structure' with full specification of nested objects and arrays, and 'uuid' is clarified as 'customer UUID'. This fully compensates for the schema's lack of documentation.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description clearly states the specific action ('Import invoices for customer'), target resource ('historical billing data'), and distinguishes from siblings by specifying it's for 'Custom API data sources' unlike other invoice-related tools like list_invoices or retrieve_invoice. The verb 'import' with 'add historical billing data' provides precise scope.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

The description explicitly states 'Use for Custom API data sources' which provides clear context for when to use this tool. However, it doesn't mention when NOT to use it or name specific alternatives among the many sibling tools, preventing a perfect score.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.