einvoice-mcp

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

No annotations are provided, so the description carries the full burden of behavioral disclosure. It states the tool returns information, implying it's a read-only operation, but doesn't mention potential side effects, error handling, rate limits, or authentication needs. This is a significant gap for a tool with no annotation coverage.

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 concise and front-loaded, with two sentences that efficiently convey the tool's purpose and utility. The first sentence lists the key information returned, and the second clarifies its use case. There's no unnecessary repetition or fluff.

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?

Given the tool's moderate complexity (2 parameters with enums) and lack of annotations and output schema, the description is somewhat complete but has gaps. It covers the purpose and general use case but omits behavioral details like response format, error conditions, or how the returned information is structured, which is important for a reference tool.

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?

The schema description coverage is 100%, with clear enum descriptions for both parameters. The description adds minimal value beyond the schema by listing topics like 'required_fields' and 'tax_categories', but doesn't provide additional context on parameter interactions or usage examples. Baseline 3 is appropriate given the high schema coverage.

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 tool's purpose: it returns information about e-invoicing formats, required fields, tax categories, unit codes, and legal deadlines. It specifies the resource (e-invoicing formats) and the type of information returned, though it doesn't explicitly differentiate from sibling tools like 'validate_invoice' or 'extract_data' beyond being a reference tool.

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 implies usage as a reference for creating valid invoices, suggesting it should be used when needing format details. However, it lacks explicit guidance on when to use this tool versus alternatives like 'validate_invoice' or 'create_xrechnung', and doesn't specify prerequisites or exclusions.

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