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

With no annotations provided, the description carries the full burden of behavioral disclosure. It indicates the operation is a read-only extraction, but it does not disclose potential errors (e.g., missing XML), output format, or any side effects beyond what the purpose already states.

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 a single, front-loaded sentence with no wasted words or redundant information. It is concise and to the point.

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 simplicity (one parameter, no annotations, no output schema), the description plus schema provide adequate context for basic usage. However, the lack of output format specification and error handling details leaves minor gaps, but not enough to reduce to a 'minimum viable' score.

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 fully describes the sole parameter pdf_content as 'Base64-kodierter Inhalt der ZUGFeRD-PDF-Datei', providing 100% coverage. The description does not add any additional parameter meaning beyond the schema, so the baseline of 3 applies.

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 uses a specific verb ('Extrahiert' = extracts) and clearly specifies the resource (embedded XML from a ZUGFeRD/Factur-X PDF). It inherently distinguishes from sibling tools like check_consistency, create_invoice, and validate_invoice, which serve different purposes.

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 (extracting XML from a PDF) but provides no explicit guidance on when to use this tool versus alternatives. It does not mention exclusions or name sibling tools as alternatives, leaving usage context only implied.

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