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 real value beyond that: the upstream source (SSA notice in the Federal Register), the effective/payment date semantics (effective December 2026, paid January 2027), and the fact that omitting the year triggers a live external API check. It does not say what the response looks like or whether the API check can be slow or fail, but with annotations present this is adequate rather than rich.

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 dense, front-loaded sentences with almost no waste. One weakness is that the hardcoded '2027 COLA is 3.6 percent' will become stale and take up space that could have been used for sibling routing.

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?

The description is simple, with two optional parameters and no output schema. The description supplies what the return contains (the rate plus history back to 1996) and the upstream source, which is enough for an agent to call it correctly. It does not say how the values are shaped or what precision or units the history values use, but this is a minor 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 coverage is 100% and both parameters are already documented in the schema, including defaults (2027, 10 years). The description mostly restates the schema's year semantics and adds only the fallback behavior when year is omitted, plus the 1996 history floor. The baseline of 3 is appropriate.

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 verb and resource: it returns the Social Security COLA rate for a payable year, sourced from the SSA Federal Register notice, plus history back to 1996. That is far more specific than the name alone. It never names a sibling, though, so the boundary with calculate_cola_increase (which presumably applies the rate to a benefit amount) must be inferred from the word 'adjustment' versus 'increase'.

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?

It describes one concrete calling mode: with no year, it queries the Federal Register API for a newer notice. That is useful behavior, but not guidance. There is no statement of when to choose this over calculate_cola_increase or get_social_security_limits, and no explicit exclusions.

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