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

Annotations already establish readOnly, idempotent, non-destructive, closed-world behavior, so the description's lower bar is met. It adds useful context about versioned rules and the percentage-versus-dollar output mode, but is silent on two behaviors the agent would care about: what applyLatestCola does and whether medicarePartBPremium reduces the returned benefit.

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?

Two sentences with no filler; the comparison range and rule basis lead, and the optional-input consequence follows. Nothing redundant is included.

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 six parameters at 0% schema coverage and no output schema, the definition should say more about the COLA flag and Medicare premium input, which are behavioral levers rather than simple filters. It does, however, fully convey the tool's computational basis and output shape, so the remaining gap is moderate rather than disqualifying.

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 0%, so the description carries the full burden, and it only meaningfully explains fraMonthlyBenefit as optional. The semantics of applyLatestCola, medicarePartBPremium, plannedClaimingAgeMonths, and the significant 1943 floor on birthYear are left entirely to bare type/min/max constraints.

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 ('Compare claiming at ages 62 through 70') and pins the mechanism to birth-year-specific full retirement age and versioned current-law adjustment rules. This is clearly distinguishable from siblings such as get_current_cola or calculate_benefit_change, which address different concerns.

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 gives one conditional usage hint in the second sentence: supplying a monthly FRA benefit yields dollar results, omitting it yields percentages only. It offers no guidance on when to choose this tool over calculating a benefit change, and no exclusions or prerequisites are stated.

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