ASO keyword research

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

Annotations already establish readOnlyHint=true and openWorldHint=true, so safety is covered. The description adds a genuine behavioral nuance beyond the annotations: the default ordering (est_keyword_downloads:desc) applied automatically and the underlying bundle's alphabetical default. It omits rate/charging behavior, though the schema's dry_run description covers the 0-request path.

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 essentially no filler, and the primary mode (by=keyword) is front-loaded. The inline bundle references are slightly noisy but serve as useful cross-references, keeping it just short of a 5.

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 14-parameter, high-coverage schema with no output schema, the description covers the key routing parameter and an important default that the schema alone does not surface. It leaves output shape unstated, but as a filtered query tool returning rows that gap is minor.

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 high (86%), so the baseline is 3, but the description goes further by explaining the semantics of the 'by' parameter (the single most important branching input) in terms of the question each value answers. It does not add field-level meaning beyond the schema, hence not a 5.

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 frames the tool's dual purpose by mapping each enum value of 'by' to a concrete question it answers ('which apps rank for this term' vs 'which terms does this app rank for'). It communicates the resource (ASO keyword/app keyword research) precisely, though it never gives a plain headline statement of the tool's overall job and relies on bundle jargon for context.

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?

It explicitly tells the agent when to use each mode: by=keyword for ranking apps on a term, by=app for terms an app ranks for. It also pre-empts a common pitfall by stating that this tool always sends order_by=est_keyword_downloads:desc unless overridden, so the agent knows the default behavior without re-deriving it.

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