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

Annotations already declare readOnlyHint=true and openWorldHint=true, covering the safety profile. The description adds nothing beyond that: no note on storefront/language scoping behavior, rate limits, or what the lookup returns when the DevID is unknown.

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?

It is a single short phrase with no waste, so structure is fine, but it is under-specified rather than genuinely concise. Nothing is front-loaded beyond the resource name.

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?

An output schema exists, so return-value explanation is not required, and all three parameters are described in-schema. However, the description never clarifies the core operation (single developer lookup vs. listing), which is the main thing an agent needs before invoking it.

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% – DevID, Country (ISO-2, default us), and Lang are all documented in the schema itself. The description adds no additional semantic detail, so the 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?

"Apple App Store developer listing" essentially restates the tool name (appstore_developer) rather than stating a specific verb and outcome. It does not say whether it returns a developer profile, their app catalog, or contact metadata, so an agent cannot distinguish it from appstore_app or appstore_search beyond the resource label.

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 when-to-use guidance, no prerequisites, and no mention of alternatives such as appstore_search or googleplay_developer. The agent is left to infer usage entirely from the name.

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