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

Annotations already declare readOnly, idempotent and non-destructive, so the safety profile is covered. The description still adds real substance beyond that: the 31-day ceiling, one data point per rate set in force including the first day, and the unit semantics of the returned rate. It does not discuss permissions or rate limits, but neither is relevant for a public read.

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?

Three tight sentences, front-loaded with the core purpose and free of filler. The 31-day restriction is stated twice (description and schema for `to`), a minor redundancy but not enough to hurt readability.

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 a full output schema, the description does not need to document return values, yet it helpfully sketches the cardinality (one point per rate set) and unit convention. Combined with the schema, annotations and the stated 31-day constraint, an agent has what it needs to invoke this correctly.

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%, so the schema already fully documents currency, from, to and language, and the description merely echoes the 31-day bound. Its one genuine addition is that each rate is the price in GEL of `quantity` units, which clarifies output interpretation more than input parameters, keeping this at the baseline.

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: official exchange rates for one currency over a bounded period, attributed to the National Bank of Georgia. It distinguishes itself implicitly from current-rate siblings via the historical/period framing, but never names rates_get_official_rates or rates_get_commercial_rates, so differentiation is inferred rather than stated.

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?

"Use it for the movement of a currency over a week or a month" gives concrete usage context, which is better than nothing. However, there are no exclusions or alternatives named, so an agent must guess whether this or rates_get_official_rates / rates_get_commercial_rates is the right call.

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