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 the output structure (keywords, theirRank, ourRank) and the meaning of a null ourRank, which is valuable behavioral context beyond a simple 'gets rivals'. It does not mention pagination or errors, but the core behavior is transparent.

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?

The description is a single, concise sentence that front-loads the core purpose and then explains the returned data efficiently. Every clause adds value, with no filler or redundancy.

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 tool with no output schema and no annotations, the description covers the essential return data and null semantics, which is sufficient for an agent to understand what to expect. It does not explicitly cover edge cases like empty results or default country behavior, but those are minor and likely inferable.

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 the schema already documents appId, country, and platform. The description adds minimal parameter context – it references 'this app' but does not elaborate on the parameters or their defaults beyond what the schema provides. Baseline 3 is appropriate.

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 tool's purpose: it returns apps ranking above the specified app in search, and details the data for each rival (keywords, their rank, our rank, and null semantics). This is a specific verb-resource pair that distinguishes it from siblings like get_keywords or get_charts, which focus on different aspects.

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?

Usage is implied by the description – it is for seeing competitors ranking above the app – but there is no explicit guidance on when to use it versus alternatives or when not to use it. No sibling alternatives are mentioned, leaving the agent to infer its place among the listed tools.

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