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

Annotations already cover the safety profile (readOnly, non-destructive, closed-world), so the description's added value is in disclosing result ordering (AppAgg Score) and the 30-day/pre-order content window, which the schema does not state. It leaves pagination behavior and total result counts unmentioned, which keeps it from a 5.

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?

Three sentences, zero filler: capability and content scope first, then concrete usage examples, then the disambiguation pointer to the sibling. The most decision-relevant facts are front-loaded.

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 5-parameter filtered list tool with an output schema (so return shape needn't be explained) and annotations covering safety, the description is complete: it covers content scope, ordering, examples, and sibling routing. The only omission, pagination, is already handled by the `page` parameter's own schema documentation.

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% and the enums for `type`, `price`, and `platform` are already richly documented in the schema, so the description correctly relies on them. It reinforces 'currently on sale (DEAL)' but adds no syntax or constraint detail (e.g. min_discount interaction with type) beyond what structured fields provide. 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 and resource ('List the best apps and games') plus the exact content window (released in last 30 days, pre-orders, or currently on sale) and ranking basis (AppAgg Score). The NEW/DEAL split maps directly to the required `type` parameter, so an agent can tell immediately what this tool returns versus the search sibling.

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?

Gives concrete example questions ('best new Android games', 'iOS apps on sale today') that anchor the intended query shape, and explicitly routes named-entity lookups to appagg_search_apps. That is an explicit when-to-use plus a named alternative with the condition that selects it.

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