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

Annotations already establish read-only, idempotent, non-destructive, open-world behavior, so the description is not burdened with safety disclosure. It adds useful context beyond annotations: BLS CPI as the source, the specific rate measures returned, series-specific historical coverage, and the caveat about the missing October 2025 index.

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 a single dense sentence that front-loads the core purpose and then lists the returned measures and coverage. The parenthetical caveat about October 2025 earns its place, though the sentence is somewhat run-on.

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 two-parameter tool with full schema coverage and annotations covering safety, the description supplies the important domain context: source, measures, year ranges, series differences, and a data-quality caveat. Exact response field names are not specified, but the returned components are described and no output schema exists.

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 baseline is 3. The description still adds meaning beyond the schema by clarifying that CPI-U and CPI-W cover 1914 onward while core CPI begins in 1958, and by explaining current-year behavior.

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: it returns the official U.S. inflation rate for a calendar year from BLS CPI data, including annual-average, December-to-December, and current-year 12-month rates. It is clear what the tool does, but it does not explicitly distinguish itself from siblings such as get_latest_cpi or calculate_inflation.

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 usage for calendar-year official inflation rates and notes current-year latest 12-month behavior, but it does not explicitly say when to use this tool versus get_latest_cpi, calculate_inflation, or compare_raise_to_inflation. Guidance is therefore 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.