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

Annotations already declare readOnlyHint, openWorldHint, idempotentHint, and destructiveHint. The description adds value by detailing the data source (FRED spot rates, DXY), the return structure (advice per pair, DXY regime, regional rollup, best/worst corridors), and the 1h cache. This goes beyond the annotations without contradiction.

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 a single paragraph that efficiently conveys purpose, scope, outputs, and differentiation. Every sentence adds value, but it could be slightly more structured (e.g., bullet points) for quick scanning. Still, it is not verbose.

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?

Given the tool has no parameters and a rich output schema (not shown but known), the description fully covers what the agent needs: the currency pairs, output categories, DXY regime, regional rollup, best/worst corridors, data sources, and cache policy. It is complete for effective invocation.

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?

The input schema has zero parameters, so schema description coverage is 100%. The description does not need to add parameter meaning, and the baseline of 4 is appropriate. The description implicitly explains that no parameters are needed—the tool provides a fixed set of intelligence.

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 clearly states the tool's purpose: per-pair execution risk assessment for 10 major currency corridors against USD. It specifies the exact output categories (SETTLE_NOW, etc.) and distinguishes from oracle.stability, making it unambiguous and distinct from siblings.

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?

The description explicitly tells when to use this tool: to answer 'which currency pairs are risky to settle through right now?' and contrasts it with oracle.stability. However, it does not differentiate from other closely related siblings like fx.corridors or fx.rate, which limits full guidance.

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