cdc_death_rates_historical

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

Annotations already declare readOnlyHint, idempotentHint, openWorldHint, and destructiveHint=false, so the safety profile is covered. The description adds useful context about age adjustment and the 120+ year range, but does not mention pagination, rate limits, or other runtime behavior. That is acceptable given the low annotation burden.

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 three compact lines: the operation, the allowed causes, and a use-case framing. The '120+ years' phrase slightly repeats 'since 1900,' but it reinforces the long-term trend purpose, so no sentence is wasted.

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 simple query tool with zero required parameters, full schema coverage, and strong safety annotations, the description provides enough context about data scope and intended use. It does not describe the shape of response rows, but the tool is simple enough that this is not a critical gap.

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 the schema already documents every parameter. The description's cause list duplicates the enum and adds no new parameter semantics beyond what is already in the schema. Baseline 3 is appropriate here.

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 opens with a specific verb and resource: 'Get age-adjusted death rates for major causes since 1900.' It also lists the exact cause values, making the tool's scope immediately clear. It does not explicitly differentiate from sibling tools like cdc_mortality_rates, but the historical framing is strong enough to avoid major confusion.

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 phrase 'Great for long-term trend analysis — 120+ years of data' gives a concrete use case and implies the tool is best suited for historical spans. It does not name alternatives or exclusions, so it stops short of a 5, but the intended context is clear.

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