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

Annotations already declare readOnlyHint, idempotentHint, closed-world and non-destructive behavior, so safety is covered. The description adds meaningful context beyond annotations: the authoritative IRS sources (Rev. Proc. 2024-40, Rev. Proc. 2025-32), the OBBBA standard deduction increase, and the fact that Social Security wage base and Medicare thresholds are also returned. It does not disclose error behavior or result shape, but the annotations and explicit extra returns make this nearly complete.

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 front-loaded with the primary return values, then adds provenance and supplementary returns in a tight, information-dense package. Every clause contributes useful detail, and there is no filler.

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 two-parameter lookup tool with rich annotations and no output schema, the description is complete: it specifies what is returned (brackets, deduction, SS wage base, Medicare thresholds), the authoritative sources, and the supported years. An agent has enough information to call it correctly without needing return-value documentation.

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% and both parameters have enums and descriptions, so the schema already carries the parameter semantics. The description confirms the tax-year and filing-status inputs but adds no syntax, defaults, or special-case guidance beyond what the schema states. 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 uses a specific verb ('Returns') and names the exact resources: federal income tax brackets (rate, lower/upper bound, tax on lower brackets) plus the standard deduction, keyed to tax year and filing status. It is immediately distinguishable from the calculation-oriented siblings like calculate_take_home_pay.

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 makes the retrieval use case clear (look up brackets and deduction for a given year/filing status) and hints at scope with the two allowed years. However, it does not explicitly say when to use this rather than a sibling calculator or name alternatives, so an agent must infer the boundary.

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