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

Annotations already declare readOnlyHint, idempotentHint, non-destructive and closed-world, so the safety profile is covered. The description adds genuinely new behavioral information: results are partitioned into active/upcoming first and past second, with newest-first ordering inside each group, which matters for how an agent interprets the returned list. It stops short of describing pagination behavior or how the limit interacts with that ordering.

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 tight sentence with zero filler, and the most important scoping constraint (one app, one storefront) is front-loaded before the ordering detail. The fragmentary construction is efficient but slightly under-formal for a tool description.

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 does explain the shape of the result (active/upcoming then past, newest first), which is helpful. However, for a 4-parameter tool with 0% schema coverage, it omits the role of limit and language, gives no default for limit, and says nothing about what happens when an app has no events in that storefront.

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% across 4 parameters, so the description must carry the meaning. 'One app in one storefront' indirectly conveys appId and country, but the limit parameter (1-200) and especially the language parameter — which plausibly controls the localization of event names and copy — are never mentioned, leaving half the surface undocumented anywhere.

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?

Names the specific resource (App Store In-App Events) and bounds it precisely to one app in one storefront, which implicitly maps to appId/country and separates it from siblings such as get_app_versions, get_app_ads, or creative_changes. It lacks an explicit verb ('returns'/'lists'), so it reads as a noun phrase rather than a stated action.

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?

Usage is only implied by the resource name: an agent can infer 'call this when you need a live/upcoming events calendar for an app in a storefront.' There is no explicit when-to-use, no exclusion of alternatives like get_app_versions or creative_changes, and no mention of prerequisites such as needing a valid numeric appId.

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