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

Annotations already declare read-only, idempotent, non-destructive. The description adds genuinely useful behavior beyond that: it discloses the rate source (daily central-bank rate where held, otherwise annual average) and that the response reports which was used. It doesn't cover error cases or direction-ambiguity handling, keeping it from a 5.

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 tight sentences with no waste; scope, optionality, and rate-source behavior are all front-loaded and dense with signal.

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 helpfully notes that the result indicates which rate was used, and it explains the conversion and inflation modes. Minor gaps remain around default `to` behavior and the default date (though the schema covers the latter).

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 40%, with only date and inflate_to_year documented in the schema. The description clarifies the currency set for from/to and implies inflation semantics, but does not address the meaning of `to` being optional (default target currency) nor that one side must be USD. It partially compensates but leaves real gaps.

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 (converts) and resource (currency amount) with the exact currency scope (USD vs GTQ, HNL, NIO, CRC, PAB, BZD, DOP) and adds the inflation-adjustment capability. An agent can immediately tell what this does and which currencies are in scope.

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: convert an amount on a date, optionally inflated to another year. There is no explicit when-to-use/when-not guidance or named alternative, though none of the sibling tools overlap on currency conversion, so this is adequate but unstated.

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