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

Annotations already declare readOnlyHint, idempotentHint and non-destructive, so the safety profile is covered. The description adds real behavioral context beyond that: the year status concept (current vs amended with amended_by), a last-verified timestamp, and citation back to the IRS document/section, plus the explicit scope limits (no advice, no state taxes). It does not mention rate limits or the availability window beyond the two listed years.

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?

Front-loaded with the trigger condition and examples before parameters and return shape, and every sentence carries information. The example-query list is slightly long relative to the two short sentences that follow, but nothing is redundant with the schema.

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 an output schema present, the description needn't detail return values, yet it helpfully summarizes the salient fields (figure, IRS source, amended status, last verified). Annotations cover safety and the scope limits cover misuse. The one missing piece is routing relative to sibling tools with overlapping concerns, notably get_mileage_rate.

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 year, topic and filing_status are already fully documented in the schema with enums and the 'leave out for every status' note. The description restates the same value lists and adds only the example natural-language phrasing that maps to those values, which is helpful but marginal. 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 states a specific verb and resource (look up published US federal tax figures) and grounds it with four concrete example queries that map to real fetches. An agent can immediately tell this is a static published-figure lookup rather than a calculator like estimate_federal_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?

Strong triggering guidance: 'Use this when the user asks for a published US federal tax figure', plus exclusions ('does not give advice and does not cover state taxes'). However, it never addresses the sibling get_mileage_rate, whose scope overlaps with the 'mileage' topic value here, nor does it distinguish itself from estimate_federal_tax, which an agent could easily confuse with a tax-figure request.

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