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

Annotations already declare read-only, idempotent, non-destructive and open-world, so the description correctly does not repeat safety claims. It adds genuinely new behavior: the arithmetic (prior-year Q3 CPI-W average over the year-earlier quarter, rounded to 0.1%), the data source with a live check against official BLS values, and that Q3 index values are returned alongside the result.

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?

Front-loads the purpose and formula, then the data source and coverage in three tight sentences with no filler. The 2027 verification detail is a little dense but does real work by showing expected output shape.

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 no output schema, the description usefully discloses what comes back (COLA percentage plus the underlying Q3 index values). Formula, data provenance, rounding precision, and historical range are all covered; only explicit alternative-tool routing is missing.

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 coverage is 100% and the single parameter is already documented as 'Year the COLA is paid, measured on Q3 of the prior year'. The description's 'covers 1976 onward' merely restates the schema minimum, adding no new syntax, format, or edge-case meaning.

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 ('Computes the Social Security cost-of-living adjustment') and pins down the exact statutory method, so it is clearly not just a generic inflation calculation. It never names or routes against the siblings (get_latest_cpi, calculate_inflation), so it falls short of full sibling differentiation.

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?

Usage is implied by the year-based framing and the 'covers 1976 onward' range, and the 2027 example signals the intended input convention. There is no explicit when-to-use-this-vs-alternatives guidance, e.g. when an agent should pick this over calculate_inflation or get_latest_cpi.

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