calculate_french_income_tax

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

Annotations already declare readOnlyHint, idempotentHint, openWorldHint. Description adds 'Read-only and deterministic: same inputs always give the same result; no data is stored' and 'Not tax advice.' Also details return values (total tax, effective/marginal rates, per-bracket breakdown), compensating for missing output schema.

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?

Five well-structured sentences, each serving a distinct purpose (purpose, usage, inputs, outputs, determinism/disclaimer, sibling alternative). Front-loaded with essential info. No wasted words.

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?

Given tool complexity (progressive brackets, family quotient, deterministic), description covers all crucial aspects: year, legal basis, input semantics, output structure, safety properties, and sibling differentiation. No output schema, but description details returns. Complete for agentic use.

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 covers 100% parameters with descriptions. Description goes further with examples: 'e.g. 2 for a married couple, 2.5 with one child' for parts, and clarifies income as 'annual net taxable income in EUR'. Adds meaningful context beyond 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?

Clearly states verb 'calculate' and resource 'French personal income tax' with explicit reference to 2026 tax year, official brackets (Article 197 CGI), and family-quotient system. Distinguishes from sibling tool calculate_french_salary for payroll calculations.

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?

Explicitly says 'Use when the user asks how much income tax they owe in France' and provides clear alternative: 'For payroll gross-to-net conversion use calculate_french_salary instead.' This tells both when to use and when not to.

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