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

Annotations already declare readOnlyHint, idempotentHint, and openWorldHint=false, so the safety profile of this pure calculation is covered. The description adds useful domain context (the 62/70 percentage rules, 2026 bend points, the 62-70 comparison scope) but does not disclose that results are estimates or what the response contains, so it adds only moderate value beyond annotations.

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 tightly packed sentences front-load the concrete payoff (70% vs 124%) and the core capability, with a reference URL appended. Nothing is filler, though the URL is peripheral to tool selection and resting phrasing could be slightly tighter.

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 zero-required-parameter, fully-schema-documented calculation tool whose annotations already cover read-only/idempotent behavior, the description gives enough to call it correctly and hints that output is a cross-age comparison. With no output schema, a brief note on the returned fields would have made it fully complete.

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 all five parameters (aime, mode, salary, claimAge, birthYear) are already fully documented in the schema. The description's mention of the 62-70 range loosely relates to claimAge but adds no parameter-level meaning. Baseline 3 applies when the schema does the heavy lifting.

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 names specific actions (estimate your PIA, compare every claiming age from 62 to 70) and the resource (US Social Security claiming benefits), with concrete figures like 70% at 62 and 124% at 70. However, with many regional siblings (jordan_social_security_calculator, egypt_social_insurance_calculator, gosi_calculator), it never explicitly states this is the US system, leaving sibling disambiguation to inference from 'PIA' and 'bend points'.

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 implies the use case (comparing claiming ages, estimating a benefit) but offers no explicit when-to-use guidance, no prerequisites, and no alternative named among the regional social-security/insurance siblings. Usage is implied rather than stated.

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