App details

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

Annotations already declare readOnlyHint=true and openWorldHint=true, so the safety and reach profile is known. The description adds the useful fact that the response is a rich field-level payload, but says nothing about error behaviour when neither identifier is supplied, rate limits, or how the optional `ratings` extra request affects latency.

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 tight sentences with the main purpose front-loaded and the identifier rule appended, no filler. The parenthetical field list is long but earns its place because no output schema exists to describe the return shape.

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?

With no output schema, the description usefully enumerates what comes back, and it names the alternative identifier inputs. What is missing is the failure behaviour when both/neither identifier is given and any note about the cost of the optional ratings lookup, which matters for a 5-parameter tool with zero required parameters.

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 coverage is 100%, so all five parameters are documented in the schema itself, establishing the baseline of 3. The description adds only the either/or relationship between `id` and `appId`, which the schema does not encode (both are optional, none required), but leaves the exact-one requirement ambiguous.

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 ('Get full details for an App Store app') and enumerates the returned fields (title, description, price, rating, version, developer, screenshots), which distinguishes it from list/search siblings. It does not explicitly differentiate from near-neighbours like app_ratings or app_privacy, which cover subsets of the same 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?

The only guidance is 'Provide either `id` or `appId`', which is an invocation constraint rather than a when-to-use rule. There is no statement about when to prefer this over sibling tools such as app_ratings (for the histogram), app_privacy, or search_apps for discovery.

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