cdc_life_expectancy

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

Annotations already provide readOnlyHint: true, so the read-only nature is clear. The description adds the year range and data endpoint (up to 2018), but does not explain behavior like default limit or pagination beyond what schema provides.

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?

Very concise: three short sentences. First sentence states purpose, second lists allowed values, third provides usage guidance. No superfluous text.

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?

Given the simple query tool with full schema coverage and readOnly annotation, the description is mostly complete. However, it does not mention the limit parameter's default or behavior, and no output schema is provided.

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?

Input schema has 100% description coverage; each parameter is already described. The description repeats the enum values and year range, which are already in the schema. Adds no new parameter meaning beyond what the schema provides.

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 clearly states 'Get U.S. life expectancy at birth by race and sex (1900–2018)', which includes a specific verb and resource. It also lists the allowed values for race and sex, and notes the year range, distinguishing it from the sibling tool cdc_mortality_rates.

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?

Explicitly advises when to use this tool versus alternatives with 'Note: Data goes through 2018. For more recent mortality trends, use cdc_mortality_rates.' Also lists the valid enum values for race and sex, clarifying filtering options.

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