Create KSeF Invoice (FA(3) XML)

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

Annotations only indicate non-read-only and non-idempotent behavior. The description adds that the API performs authoritative fiscal validation, can optionally submit through a provider integration, and requires prior onboarding/configuration. This goes beyond the structured hints, though it doesn't cover failure behavior or response format.

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?

Two concise sentences, front-loaded with the primary function and followed by operational context. Every sentence earns its place without filler.

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?

This is a complex create tool with a large nested input and no output schema. The description covers high-level behavior and prerequisites but omits return value, validation failure behavior, and how the 'integration' object affects submission. More operational context would help the agent invoke it correctly.

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 covers 50% of top-level parameters with rich nested descriptions for 'data', so the schema does much of the work. The description contributes no parameter-specific guidance and doesn't compensate for undocumented top-level parameters like site_url, site_title, and plugin_version.

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 starts with a specific verb and object: 'Generate a Polish KSeF FA(3) XML invoice or credit note.' It clearly identifies the document format and distinguishes this tool from siblings like SDI, Zugferd, and Peppol.

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: it performs authoritative KSeF fiscal validation and can optionally submit via the configured provider, with a prerequisite that onboarding/legal-entity configuration be completed. It doesn't explicitly name alternatives or state when not to use it, but the Polish KSeF scope is evident from the title and first sentence.

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