generate_invoice_ubl

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

With no annotations, the description carries the full burden. It discloses the return type (XML as text) and the API key requirement. However, it does not mention any side effects, rate limits, or confirm that the tool is non-destructive. More behavioral context would be beneficial.

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 two sentences, front-loading the core purpose and exclusions, then providing return type and prerequisite. Every word adds value, and no unnecessary detail is present.

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 complexity (20 parameters, nested objects, no output schema), the description covers the essential return type and non-compliance caveat but lacks guidance on parameter usage, error handling, or the expected XML structure. It is adequate for a simple tool but incomplete for a complex one.

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 description does not elaborate on any parameters, leaving all semantic value to the input schema, which has 60% coverage. The schema provides some descriptions, but the description itself adds no additional meaning for the remaining 40% of parameters. This is insufficient compensation.

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 generates a UBL 2.1 XML invoice for interoperability/archival, and explicitly distinguishes from regulated e-invoice transmissions (Peppol/Factur-X/XRechnung). This uniquely identifies its purpose relative to siblings like generate_invoice_pdf and calculate_invoice_totals.

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 notes when to use (for interoperability/archival) and when not (not for regulated compliance). It also mentions the prerequisite INVOVATE_API_KEY. However, it does not explicitly compare to sibling tools or provide alternative recommendations.

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