Convert a PDF/scan directly into a ZUGFeRD PDF

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

With no annotations, the description carries the full burden, and it does disclose the internal pipeline (analysis, validation, embedding) and that the output is validated PDF/A-3. It does not state what happens on validation failure, whether the call is synchronous or long-running, any input size limits, or how the resulting PDF is returned — all material for a heavy conversion 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?

A single front-loaded sentence with the core action first and the pipeline detail in a parenthetical; no filler. Slightly dense, but every clause earns its place.

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 conversion tool with no output schema and no annotations, the description should say what comes back (base64 payload, file path, download URL?) and how failures surface. It conveys the product but leaves the return contract unstated, which is the main gap an agent needs to plan around.

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 100%, so both parameters are already documented (fileName, pdfBase64 with accepted formats). The description adds no syntax, encoding, or size detail beyond the schema, so the baseline 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?

States a specific verb and resource: convert a PDF or scanned image invoice into a validated ZUGFeRD PDF/A-3. The input-domain phrase ('from a PDF or scanned image') implicitly separates it from create_zugferd_pdf, but the sibling is never named, so the agent must infer the distinction rather than being told it.

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?

'in one call (analyzes, validates, and embeds in a single step)' implies when this is preferable to the multi-step analyze_* + create_zugferd_pdf path, which is useful implied guidance. However, no alternative is named explicitly and no preconditions (e.g. input must already be an invoice) are stated.

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