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

Annotations already indicate readOnlyHint=true and openWorldHint=false. The description adds valuable behavioral context: it is a deterministic threshold rule, explicitly states 'no AI', and lists the exact return values (eligibility, share, threshold, data year). No contradiction with annotations.

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 compact and front-loaded with the key threshold, followed by user applicability and return values. It includes a redundant French duplicate of the opening phrase, which costs a little conciseness, but overall every major point is stated efficiently.

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 two-parameter deterministic calculator with no output schema, the description is complete: it states the rule, the eligibility criterion, the benefit, and the exact outputs. No additional context is needed to invoke or interpret the result.

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 swiss_income and total_income are already fully documented in the schema. The description adds conceptual framing (household worldwide income, taxable in Switzerland) but does not provide additional parameter-level detail 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?

The description clearly states the tool's purpose: it tells a Geneva cross-border worker whether they qualify as a quasi-resident. It names the specific verb/resource/scope and distinguishes itself from sibling tools like calculate_net_swiss_salary and check_zone_tendue.

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 clearly identifies the target user and context: Geneva cross-border workers considering itemised deductions. It does not explicitly name alternatives or state when not to use it, but the context is specific enough to guide selection.

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