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

Annotations already cover the safety profile (readOnlyHint, openWorldHint), so the description adds real value by disclosing the billing model ('Costs 1 credit per record returned (minimum 2)') and advising to keep page_size minimal. This cost/permission context goes beyond what annotations provide, though return-format behavior is left to the output schema.

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 sentences, front-loaded with the core purpose followed by routing and cost guidance. Slight redundancy in listing 'app, country, score, or query' (already in the schema), but overall efficient with no wasted filler.

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?

Given an output schema exists, the description needn't explain returns. It covers purpose, routing, filter/sort capabilities, and the credit cost, which is sufficient for a search tool with 8 well-documented parameters and clear annotations.

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?

With 100% schema description coverage, the schema already documents all 8 parameters. The description restates store values and the filter/sort fields but adds no syntax or format detail beyond the schema, so the 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 ('Search') and resource ('the stored iOS App Store and Google Play review dataset, one document per review'), which is precise and distinguishes it from the live platform review siblings. An agent can immediately tell this is a dataset search rather than a per-platform endpoint.

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 names the alternatives explicitly ('Use appstore_reviews or googleplay_reviews for the platform review endpoints') and lists the filterable/sortable fields. The selection condition is clear but slightly loose — it implies 'stored dataset' vs 'platform endpoint' without stating exactly when each is preferable.

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