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

Annotations already declare readOnlyHint=true, idempotentHint=true, destructiveHint=false and a closed world, so the safety profile is covered. The description adds one genuinely useful behavioral fact — that the output is an educational estimate with no official SSA authority — but says nothing about calculation assumptions, rounding, or how a missing Part B premium is handled.

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 written sentences with zero padding; the core action is front-loaded and the caveat follows directly. Every clause earns its place.

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?

There is no output schema, and the description partially compensates by naming the two returned quantities (monthly and annual change). But with two undocumented parameters and an unstated calculation basis, an agent still lacks enough to invoke this confidently beyond the single required field.

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 0% for two parameters, so the description carries the burden and largely fails it. 'Monthly benefit change' loosely implies currentMonthlyBenefit is a monthly dollar figure, but medicarePartBPremium is never mentioned, and no units, formats, or bounds are given for either input.

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 a specific action (estimate monthly and annual benefit change) and the data source (COLA Insight's latest tracked rate), so an agent can tell this is a computation rather than a data-fetch like the get_cola_* siblings. It stops short of explicitly contrasting itself with those siblings, but the verb+resource pairing is unambiguous.

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 'educational estimate' framing and the disclaimer that it is not an SSA determination, which hints at when the result is and isn't appropriate. However, it never says when to reach for this tool versus get_current_cola or get_cola_history, and no prerequisites (e.g. needing a current benefit amount) are stated.

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