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

Annotations already cover the safety profile (readOnlyHint true, openWorldHint false), and the description adds two things not in the structured fields: the rules are versioned to the 2026 tax year, and the output is a per-test pass/fail breakdown rather than a bare boolean. It does not say what happens in borderline or year-agnostic cases, which keeps it off a 5.

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?

A single sentence, front-loaded with the two tests being applied and closed with the reporting behaviour. Nothing is redundant or padded.

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 correctly takes on the job of saying what comes back ('which is met and which conditions fail'), and the 2026 scoping prevents stale-rule confusion. Adequate for a four-parameter read-only evaluator, though it stays silent on how partial inputs are handled when only days_in_cyprus is supplied.

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 four parameters are already fully documented, including the arrival/departure counting convention. The description references the four 60-day-rule conditions collectively but adds no format, ordering, or default guidance beyond the schema, so the baseline 3 applies.

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: applying the Cyprus 183-day test and the four 60-day-rule conditions for 2026, and reporting which is met and which fails. No sibling tool covers individual tax residency, so it is trivially distinguishable from cyprus_vat_registration_test, cyprus_audit_or_review_test and the lookup tools.

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 purpose implies when the tool applies (determining an individual's Cyprus tax residence), but there is no explicit when-to-use/when-not framing, no mention of what to do if data is incomplete, and no routing to any alternative. A single clause such as 'use when assessing an individual, not a company' would lift this.

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