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

Annotations already cover safety and determinism (readOnly, idempotent, non-destructive, closed-world), so the bar is lower. The description still adds real value beyond that: the return payload shape (result rows in page language, raw engine outputs, sources with lastChecked dates, disclaimer), the governing rules year, a last-updated date, and the source page.

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 formula and scope are front-loaded in the opening sentence, and the tax/return details are packed efficiently without filler. The dangling 'Inputs marked "Only used when"' sentence does not earn its place given no such marking exists in the schema.

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?

With no output schema, the description steps up to explain the return payload and disclaimer, and the 100%-covered input schema handles the parameters. The rules year, currency context (implied EUR), and freshness date are covered, leaving little an agent would need that is missing.

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 itself documents each parameter in detail, including the 6-month aggregate alternative and the default handling for nostradatasDienas. The description contributes only the vague 'Only used when' note, which adds little beyond the structured field descriptions – baseline 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 resource (Latvian vacation pay) and year (2026), and spells out the computation: average daily earnings times vacation days less VSAOI 10.5% and PIT with a €550 non-taxable minimum. An agent can immediately distinguish this from the sibling country/benefit calculators such as greece_annual_leave or estonia_redundancy_compensation.

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?

Usage context is implied by the country and benefit scope, but there is no explicit when-to-use guidance or named alternative. The trailing note about 'Inputs marked "Only used when"' implies conditional-input guidance, yet no such marking appears in the schema, leaving the instruction dangling and unactionable.

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