invoice_validate

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 validation targets, return type (structured report with errors/warnings), auto-detection, and parameter-driven behaviors (e.g., KoSIT fallback control). This is sufficient for a read-heavy tool.

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?

Four concise sentences, front-loaded with the main action, no unnecessary words. Every sentence adds relevant information.

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?

Despite no output schema, the description adequately explains the output format (validation report with errors/warnings). It covers all key aspects: what, against which rules, supported profiles/syntaxes, auto-detection, and key parameter effects (strict, use_local_only).

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 coverage is 100%, so baseline is 3. The description adds value by explaining that profile and syntax are auto-detected if not specified, which clarifies the optional override parameters. This goes beyond the schema's own descriptions.

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 defines the tool as validating ZUGFeRD and XRechnung invoice XML against specific standards (EN 16931, KoSIT Schematron). This distinguishes it from siblings like invoice_parse or invoice_convert, which have 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 provides clear context for use (validating invoices) and mentions auto-detection features, but does not explicitly state when to avoid or explicitly compare to alternatives. Still, the purpose is well-defined.

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