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

Annotations already declare this is a safe, idempotent, open-world read, so the bar is lower. The description still adds real context beyond them: it is free, it 'delivers no reviews' (steering review needs elsewhere), and the country influences downstream Google Play review languages.

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?

Four compact sentences, front-loaded with purpose and scope before return values and usage rules. No filler; even the terse 'Free; delivers no reviews' carries decision-relevant information.

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 values need not be fully documented, yet the description still summarizes them. Purpose, alternatives, defaults, and cost are all covered, leaving nothing an agent needs to call it correctly.

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 coverage is 100%, so baseline is 3, but the description adds meaning the schema lacks: omitting store searches both stores (no default is documented in the enum) and country's downstream effect on Google Play review languages. Minor gap only in that query syntax/keyword behavior isn't elaborated.

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?

Opens with a specific verb (Search) plus resources (App Store, Google Play) and scope (by name, one storefront country), which cleanly separates it from the review-oriented siblings rivioo_get_reviews and rivioo_search_reviews. It also names the returned fields (app_id per store, developer, rating, store links).

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?

Explicitly routes the agent: 'Use it for apps that are not in rivioo_my_apps', with a sibling named as the alternative. It also tells the agent to ask the user for the unknown country and that omitting store searches both stores, covering the main path and edge case.

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