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

With no annotations provided, the description carries the full burden. It discloses scope (Google Play and iPhone App Store only), return metrics (best rank, latest rank, ranked-day count), and date range constraints. However, it does not mention authentication, rate limits, or error behavior, which are gaps for a tool with zero annotation coverage.

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 with no filler. The core action is front-loaded, followed by concise details on return values, ranking types, exclusions, and date constraints. It's efficient and well-structured.

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?

Covers the key aspects: what it returns, limitations (iPad excluded), defaults, and max range. It describes per-dimension metrics despite lacking an output schema. Pagination is implicitly covered via the limit parameter in the schema. Given the tool's complexity, it's reasonably complete, though it could mention explicit pagination behavior.

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 each parameter is already documented in the schema. The description adds slight context (e.g., 'top-grossing' vs 'grossing') and clarifies default date range, but it doesn't add meaningful semantics beyond what the schema provides. Baseline 3 is appropriate per the high coverage.

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?

The description clearly states the verb (List) and specific resource (game rank markets) with detail on what dimensions are returned. It doesn't explicitly contrast with sibling tools like get_store_game_rank or get_store_game_rank_trend, but the specificity of countries, categories, stores, and ranking types distinguishes it enough for an agent to recognize its unique output.

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 useful context about default date range and exclusions (iPad), but does not explicitly say when to use this tool versus alternatives. The guidance is implicit through the distinct return type, but there's no direct routing like 'use this instead of get_store_game_rank for aggregated dimensions.'

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