ksef_invoice_xml

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

The readOnlyHint annotation already indicates a safe read operation. The description adds meaningful behavior beyond that: it clarifies the required active session, the FA(3) format, and the alias relationship to ksef_invoice_get. No contradiction with annotations exists.

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 three short sentences with no filler. The core action is front-loaded, the alias relationship is stated, and the session requirement is included. Every sentence contributes useful 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?

For a simple single-parameter read-only tool, the description covers the key resource, the lookup key, the XML format, the alias relationship, and the session prerequisite. It does not describe error cases or response structure, but the tool name and description already convey that the result is invoice XML, and no output schema exists to elaborate further.

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 input schema already describes the sole parameter as 'Numer KSeF faktury' with 100% coverage. The description mentions 'po numerze KSeF', which aligns with the schema but adds no additional constraints, formatting, or disambiguation beyond what the schema provides.

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 states a specific action ('Pobierz XML faktury'), a specific resource (invoice XML from KSeF), the lookup key (KSeF number), and the format (FA(3)). It also explicitly identifies itself as an alias for ksef_invoice_get, which removes ambiguity among siblings.

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 gives useful context about requiring an active session and notes that it is an alias for ksef_invoice_get, but it does not explicitly explain when to choose this tool over related alternatives such as ksef_invoices_query or ksef_draft_render_xml. Usage is implied rather than fully guided.

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