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

Annotations already declare readOnlyHint and openWorldHint, so safety is covered. The description adds the useful detail that the response contains full metadata (name, developer, ratings, price, version, size, screenshots, store URL), but says nothing about behavior on missing/unknown app ids or whether results vary by storefront.

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; the core purpose and the return payload are front-loaded and nothing is wasted.

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 field list compensates well for what the tool returns, and the schema handles the input side. Only missing is error/empty-result behavior, a minor gap for a simple read tool.

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 100%, so all four parameters are already documented including the app_id format examples and store enum. The description's identifier sentence largely restates the schema, though it does usefully tie the id format to the store value.

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+resource ('Full metadata for one app') and enumerates the fields returned, which distinguishes it from search_apps and list_categories. It stops short of naming siblings explicitly, so differentiation is implicit rather than stated.

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?

Gives identifier guidance ('use the numeric app id (iOS) or package name (Android)'), which is invocation guidance rather than when-to-use guidance. It never says when to prefer search_apps over get_app or what to do when you only have an app name.

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