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

Annotations already declare readOnlyHint, idempotentHint, openWorldHint=false and destructiveHint=false, so the safety profile is fully covered structurally. The description adds useful domain context – the available VAT rates and that 0% corresponds to alanyi adómentes – but nothing about rounding, currency handling, or output format. With annotations carrying the behavioral load, 3 is appropriate.

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 short sentences, front-loaded with the core operation before the rate details. Nothing is redundant, though it is minimal to the point that a little more operational detail could have been afforded.

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?

A pure calculation tool with three well-documented parameters, no output schema required, and a description that covers the operation, inputs, and the meaning of the result (includes the VAT amount). Rounding/currency precision is the only real omission for a money-calculation tool.

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% and both enums are documented in the schema, so the baseline is 3. The description reinforces the rate set and explains the 0% case (alanyi adómentes), which adds mild semantic value over the enum values, but it says nothing extra about osszeg or osszeg_tipusa beyond the schema.

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?

States a specific verb and resource: converts net to gross or gross to net (nettóból bruttót vagy bruttóból nettót számol) and returns the VAT amount. This clearly distinguishes it from siblings like ber_szamitas or kesedelmi_kamat, which compute different quantities. It does not explicitly name any sibling, but the arithmetic function is unambiguous.

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 implies when the tool applies (whenever a Hungarian VAT conversion is needed) via the 'nettó ↔ bruttó' framing, and the rate list signals the supported cases. However, it gives no explicit when-to-use/when-not guidance and does not reference any alternative tool for related tasks (e.g. corporate tax or late-interest siblings).

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