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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false, and openWorldHint=false, so the safety profile is covered. The description adds the substantive context that results are market combinations spanning country, language, currency and checkout availability, but says nothing about pagination or default result size.

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?

A single tight sentence with the resource scope front-loaded and no filler. It is efficient, though the abstract noun 'combinations' is slightly less concrete than saying it returns a list of markets.

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 an output schema present, return-value explanation is unnecessary, and the safety annotations are complete. However, for a three-parameter discovery tool the description is thin: it never explains filtering semantics for query or limit, which is the main gap an agent would need filled.

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 only 33%: limit and query have no schema descriptions, and the description does not explain what query matches or what limit controls. Only the availability enum is documented in the schema, and the description's mention of 'checkout availability' only loosely gestures at it.

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 states a specific verb ('Find') and enumerates the resource dimensions (country, language, currency, checkout availability), so the agent knows exactly what data set this returns. It doesn't need sibling differentiation because no sibling tool covers markets.

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?

There is no when-to-use guidance, no mention of when this is preferable to other lookups, and no prerequisite or scoping notes. The agent is left to infer that this is a discovery endpoint from the name alone.

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