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

No annotations are provided, so the description carries the full behavioral burden, yet it discloses nothing beyond the returned fields. It does not state that this is a read-only lookup, whether auth is required, what happens for an unknown appId or unsupported country, or whether results are cached/rate-limited.

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 fragment with no filler; the returned fields come first. It is efficient, though the extreme terseness edges toward under-specification rather than optimal brevity.

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 simple two-parameter read tool with no output schema, the description covers the essential 'what you get' but omits usage routing, failure behavior, and parameter meaning. Adequate at a minimum-viable level, with clear gaps.

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 0% for two required params, so the description must compensate; it partially does by framing country as 'storefront' and scoping to a single app. It still adds no format detail (the regex constraints live only in the schema) and never mentions the parameters by name.

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 names the resource (one app in one storefront) and enumerates exactly what is returned (price, rating, version), so the agent knows the shape of the data. It does not, however, distinguish itself from the close sibling get_app or explain how 'market' differs from general app data.

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?

There is no guidance on when to call this versus get_app, find_apps, or search_apps, and no prerequisites are stated. The only implied usage is 'you want price/rating/version for a known app in a known storefront,' which the agent must infer.

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