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

Annotations already declare readOnly, idempotent, non-destructive, closed-world behavior, so the safety profile is covered. The description only adds a small amount of behavioral context by noting the response includes 'public guide routes' alongside languages, but says nothing about pagination, ordering, or whether the result set is exhaustive.

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?

One tight sentence with the resource front-loaded and no filler. It is efficient, though arguably too sparse to earn a top score given the tool has an undocumented parameter.

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 carries responsibility for explaining the return value; it names the two content categories but not their shape, and it leaves the 'limit' parameter's effect unexplained. Adequate minimum, but with clear gaps.

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 single 'limit' parameter has 0% schema description coverage and is never mentioned in the description. With a maximum of 50 and a default, an agent cannot tell from the text whether the full language list is returned by default or whether it is paginated/truncated.

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 ('Return') and the exact resources: supported screenshot localization languages and public guide routes. This lets an agent distinguish it from the similar-looking sibling list_magicscreenshots_markets by resource, though the description never explicitly names that sibling.

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 prerequisites, and no mention of an alternative tool. An agent can infer this is a reference-lookup call from the name, but the description adds nothing about context or exclusions.

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