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

Annotations already declare this as a read-only, idempotent, non-destructive, closed-world operation, so safety behavior is well covered. The description adds useful scope by enumerating the returned content categories, but does not describe return shape, pagination, or data freshness beyond that.

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?

A single front-loaded sentence with no wasted words. The platform restriction comes first, followed by the resource scope and the returned data categories.

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 one-parameter read-only tool with rich annotations, the description is usable but incomplete. It lists what data appears in the drill-down, yet does not explain where listing_id comes from or what the response structure looks like, and no output schema fills that gap.

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?

The only parameter is listing_id, and schema description coverage is 0%, so the description must compensate. "One listing's" implies the parameter identifies a listing, but it does not explain the ID type, source, or format, leaving the parameter largely undocumented.

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 specifies a single-listing drill-down and names the data it exposes: screening row, prices, quarters, earnings, and news. It is clear enough to distinguish this as a detail-fetch tool from list-oriented siblings like qanvo_app_catalog or qanvo_app_alerts, though it never explicitly names an alternative.

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?

"App only" signals a platform restriction, but the description gives no explicit guidance on when to choose this tool over siblings such as qanvo_app_result or market_query. There are no stated preconditions, exclusions, or alternative paths.

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