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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false and openWorldHint=false, so safety is fully covered elsewhere. The description adds no behavioral context of its own — nothing about pagination, the default/max limit of 100, ordering, or what 'public market routes' means.

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 no filler and the resource front-loaded. It is efficient, though it is arguably too terse for the amount of undocumented surface area.

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 and zero parameter documentation, the description should explain the return shape and how region/limit shape results. Neither is covered, leaving the two optional parameters and the output format unexplained.

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 0%, so the description must carry parameter meaning, but it never mentions the 'region' enum values or the 'limit' cap. 'supported markets' loosely gestures at filtering but gives no syntax or allowed values.

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 resource ('supported App Store market guides and public market routes'), so an agent knows this is a read-only listing tool. It does not, however, distinguish itself from the parallel sibling list_magicscreenshots_languages, and 'market guides' vs 'markets' is slightly opaque.

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 statement of when to call this tool, what question it answers, or how it relates to list_magicscreenshots_languages or the get_magicscreenshots_* siblings. The agent must infer usage entirely from the name.

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