get_invoice

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

No annotations are provided, so the description carries the full burden. It does not disclose any behavioral traits such as required permissions, error conditions, rate limits, or whether the operation is purely read-only. The description only states the basic function.

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 very short and avoids unnecessary words. However, it redundantly states the same information in two languages. It could be more concise by keeping one language and more structured by adding relevant details.

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 absence of annotations and output schema, the description should provide more context about what the tool returns, error handling, and parameter details. It only covers the basic purpose, leaving out critical information for correct invocation.

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?

Schema description coverage is 50% (only 'id' has a description). The description does not add any meaning beyond the schema, particularly for the 'backend' parameter which lacks a schema description. The tool description fails to compensate for the missing parameter 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 tool retrieves an invoice by its ID. It uses a specific verb ('get' / 'abrufen') and resource ('invoice'), and it distinguishes itself from sibling tools like create_invoice, list_invoices, and update_invoice.

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 provides no guidance on when to use this tool versus alternatives (e.g., list_invoices for searching, get_invoice_pdf for PDF retrieval). There are no prerequisites or usage conditions mentioned.

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