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

With no annotations, the description carries the full burden. It discloses that Google Play is deliberately excluded and that historical data is included, adding meaningful behavioral context beyond the schema. It does not mention read-only status or error handling, but for a simple read tool this is acceptable.

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 sentences, front-loaded with the core purpose and followed by a relevant exclusion explanation. No filler or repetition; every sentence earns its place.

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?

For a 2-parameter read tool with no output schema, it covers the main points: what it returns, scope, and why Google Play is excluded. Minor gap: the schema marks country as optional but the description implies it is needed, which could cause slight confusion.

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% for both parameters, each with descriptive text. The description adds no new parameter-level meaning beyond reinforcing that it is per-country, which is already in the schema. Baseline 3 applies.

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 (get) and resource (App Store chart position) with clear scope: one country, list types (free/paid/grossing), and category. It explicitly distinguishes from Google Play, which sets it apart from any potential sibling tool. The purpose is unambiguous and actionable.

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?

Provides clear context (App Store, one country) and an explicit exclusion (Google Play) explaining why it is absent. However, it does not name alternative tools or state when to prefer siblings like get_history, so the routing guidance is only partial.

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