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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint=false, so the safety profile is covered by structured data. The description adds useful behavioral scope: the basic personal amount is credited at the lowest rate and employment-specific credits are excluded, which affects how results should be interpreted. It says nothing about rounding, tax-year versioning, or precision limits, which matters for a tax calculation.

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?

Three tightly packed sentences with the purpose and scope front-loaded before the alternative route. The trailing enumeration of return fields ({income_cad, basic_personal_amount, ...}) is partially redundant given an output schema exists, and is the one piece that does not earn its space.

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?

The description covers scope, exclusions, the sibling alternative, and bundle discovery; annotations cover safety; and an output schema covers return values. Nothing an agent needs to select and invoke this tool correctly 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?

There is a single parameter and schema description coverage is 100%, so the schema already defines 'income_cad' as annual income in CAD with a minimum of 0. The description adds no syntax or format detail for the parameter itself; its added meaning (lowest-rate BPA credit) is about the calculation, not the input. 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 ('Calculate Quebec provincial income tax (Revenu Québec)') and immediately bounds the scope by naming what it does not cover (employment credits: QPP/QPIP/EI, worker deduction). This cleanly separates it from the many sibling tax calculators such as calculate_canada_combined_tax, calculate_canada_federal_tax, and calculate_belgian_income_tax.

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 gives the when-not ('Excludes employment-specific credits ... for a salary use calculate_canada_combined_tax') and names the alternative tool plus the condition that selects it. It also points to list_bundles for related 'finance-afrique-quebec' calculators, which helps discovery.

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