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

Annotations already declare the tool as read-only and idempotent, so safety is covered. The description adds valuable behavioral context beyond annotations by clarifying the pricing model (PLN net, one-time purchase, no subscription) and the scope of the feature matrix, which helps the agent set expectations about the returned information.

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 a single, compact sentence that front-loads the core purpose before elaborating on what is compared. Every phrase adds useful detail (editions, currency, one-time purchase, feature categories), with no filler or redundancy.

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 read-only comparison tool with a fully documented schema and safety annotations, the description is largely complete: it states what is compared, the pricing terms, and the feature areas covered. It does not describe the exact output structure, but the absence of an output schema is mitigated by the explicit mention of prices and a feature matrix.

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 the schema already documents both parameters ('editions' and 'onlyDifferences') adequately. The description reinforces the edition names but adds no meaning beyond the schema, so the baseline score of 3 is appropriate.

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 verb ('Compare'), a precise resource ('Faktura VAT 2027 editions'), and enumerates the exact editions (START, STANDARD, PRO). It also specifies the comparison dimensions (prices and feature availability matrix), making it clearly distinct from sibling tools that focus on FAQs, KSeF info, product info, or knowledge base searches.

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 when to use the tool: whenever an agent needs to compare editions of Faktura VAT 2027. It does not explicitly name alternatives or state when not to use it, but the sibling tools serve obviously different purposes, so an agent can infer the right selection without ambiguity.

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